diff --git a/src/app/login/page.tsx b/src/app/login/page.tsx
index fd152fbd..e13ce259 100644
--- a/src/app/login/page.tsx
+++ b/src/app/login/page.tsx
@@ -2,13 +2,11 @@
 
 import React, { useState } from "react";
 import { LoginForm } from "@/features/auth/ui/LoginForm/LoginForm";
-import { Modal } from "@/shared/ui/Modal/Modal";
 import { useRouter } from "next/navigation";
 import { useAuthStore } from "@/features/auth/model/auth.store";
 
 export default function SignUpPage() {
   const router = useRouter();
-  const [errorMessage, setErrorMessage] = useState<string | null>(null);
   const { setIsLogined } = useAuthStore();
   return (
     <div className="flex min-h-[calc(100vh-70px)] flex-col items-center justify-center px-4 md:min-h-[calc(100vh-80px)] xl:min-h-[calc(100vh-100px)]">
@@ -19,19 +17,7 @@ export default function SignUpPage() {
           setIsLogined(true);
           router.push("/"); //메인 페이지 이동
         }}
-        onError={(msg) => {
-          setErrorMessage(msg);
-        }}
       />
-
-      {!!errorMessage && (
-        <Modal
-          message={errorMessage}
-          buttonText="확인"
-          onClick={() => setErrorMessage(null)}
-          className=""
-        />
-      )}
     </div>
   );
 }
diff --git a/src/app/my/page.tsx b/src/app/my/page.tsx
index c6ce3d3d..e734718b 100644
--- a/src/app/my/page.tsx
+++ b/src/app/my/page.tsx
@@ -7,7 +7,7 @@ import Tab from "@/widgets/mypage/ui/Tab.tsx/Tab";
 import { apiFetch } from "@/shared/api/fetcher";
 import { useModalStore } from "@/shared/model/modal.store";
 import { usePostCreateModal } from "@/features/createPost/lib/usePostCreateModal";
-
+import { handleError } from "@/shared/error/errorHandler";
 const options = [
   { label: "판매중 상품", value: "selling" },
   { label: "판매완료 상품", value: "sold" },
@@ -48,7 +48,7 @@ const Mypage = () => {
       });
       setUserProfile(data);
     } catch (error) {
-      console.error("유저 정보 로딩 실패: ", error);
+      handleError(error, "유저 프로필을 불러오는 중 오류가 발생했습니다.");
     }
   }
 
@@ -68,7 +68,7 @@ const Mypage = () => {
       );
       setPosts(res.data);
     } catch (error) {
-      console.error("현재 유저 관련 게시글 불러오기 실패 : ", error);
+      handleError(error, "현재 유저 게시물을 불러오는 중 오류가 발생했습니다.");
       setPosts([]);
     } finally {
       setLoading(false);
diff --git a/src/entities/chat/lib/useChatOtherUser.ts b/src/entities/chat/lib/useChatOtherUser.ts
index c14015ba..e17fbd3d 100644
--- a/src/entities/chat/lib/useChatOtherUser.ts
+++ b/src/entities/chat/lib/useChatOtherUser.ts
@@ -1,12 +1,11 @@
 import { useEffect, useState } from "react";
 import { User } from "@/entities/user/model/types/user";
 import { apiFetch } from "@/shared/api/fetcher";
-import { useModalStore } from "@/shared/model/modal.store";
+import { handleError } from "@/shared/error/errorHandler";
 
 export const useChatOtherUser = (otherId: number) => {
   const [otherUser, setOtherUser] = useState<User | null>(null);
   const [isLoading, setIsLoading] = useState(false);
-  const { openModal, closeModal } = useModalStore();
 
   useEffect(() => {
     async function fetchUser() {
@@ -16,11 +15,8 @@ export const useChatOtherUser = (otherId: number) => {
           method: "GET",
         });
         setOtherUser(res);
-      } catch {
-        openModal("normal", {
-          message: "상대 유저 정보 조회에 실패했습니다.",
-          onClick: () => closeModal(),
-        });
+      } catch (error) {
+        handleError(error, "상대 유저 정보를 가져오는 중 오류가 발생했습니다.");
       } finally {
         setIsLoading(false);
       }
diff --git a/src/entities/chat/lib/useChatPost.ts b/src/entities/chat/lib/useChatPost.ts
index 30cab466..8901f831 100644
--- a/src/entities/chat/lib/useChatPost.ts
+++ b/src/entities/chat/lib/useChatPost.ts
@@ -2,6 +2,7 @@ import { useEffect, useState } from "react";
 import { PostDetail } from "@/entities/post/model/types/post";
 import { apiFetch } from "@/shared/api/fetcher";
 import { useModalStore } from "@/shared/model/modal.store";
+import { handleError } from "@/shared/error/errorHandler";
 
 export const useChatPost = (postingId: number) => {
   const [post, setPost] = useState<PostDetail | null>(null);
@@ -16,11 +17,8 @@ export const useChatPost = (postingId: number) => {
           method: "GET",
         });
         setPost(res);
-      } catch {
-        openModal("normal", {
-          message: "게시물 정보 조회에 실패했습니다.",
-          onClick: () => closeModal(),
-        });
+      } catch (error) {
+        handleError(error, "게시물 정보 조회 중 오류가 발생했습니다.");
       } finally {
         setIsLoading(false);
       }
diff --git a/src/entities/chat/model/socket.ts b/src/entities/chat/model/socket.ts
index 702de261..2dace2c3 100644
--- a/src/entities/chat/model/socket.ts
+++ b/src/entities/chat/model/socket.ts
@@ -1,7 +1,8 @@
-import { error } from "console";
 import { MessageProps } from "./types";
 import { useAuthStore } from "@/features/auth/model/auth.store";
 import { refreshAccessToken } from "@/shared/api/refresh";
+import { handleError } from "@/shared/error/errorHandler";
+import { ServerError } from "@/shared/error/error";
 
 export interface ChatSocketEvents {
   onOpen?: () => void;
@@ -62,7 +63,11 @@ export class ChatSocket {
             this.events.onMessage?.(msg);
           }
         } catch (err) {
-          console.error("[Socket] Message parse error:", err);
+          handleError(
+            new ServerError(undefined, () => {
+              location.replace("/");
+            }),
+          );
         }
       };
 
@@ -79,7 +84,11 @@ export class ChatSocket {
       };
 
       this.socket.onerror = (err) => {
-        console.error("[Socket] Error:", err);
+        handleError(
+          new ServerError(undefined, () => {
+            location.replace("/");
+          }),
+        );
         this.events.onError?.(err);
         reject(err);
       };
diff --git a/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx b/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx
index 20fc8ea1..1837c6a8 100644
--- a/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx
+++ b/src/entities/chat/ui/ChattingRoom/ChattingRoom.tsx
@@ -15,6 +15,7 @@ import { useInfiniteScroll } from "@/shared/lib/useInfiniteScroll";
 import { getPostDetail } from "@/entities/post/api/getPostDetail";
 import { getUser } from "@/entities/user/api/getUser";
 import { useQuery } from "@tanstack/react-query";
+import { handleError } from "@/shared/error/errorHandler";
 
 export const ChattingRoom = ({
   postingId,
@@ -157,11 +158,8 @@ export const ChattingRoom = ({
           },
         );
         setChatId(res.chatId); //useChatSocket hook을 통한 소켓 자동 재연결.
-      } catch {
-        openModal("normal", {
-          message: "채팅방 생성에 실패했습니다.",
-          onClick: closeModal,
-        });
+      } catch (error) {
+        handleError(error, "채팅방 생성 중 오류가 발생했습니다.");
       }
     }
 
diff --git a/src/features/auth/ui/LoginForm/LoginForm.tsx b/src/features/auth/ui/LoginForm/LoginForm.tsx
index b2810fb6..8a5b9bbb 100644
--- a/src/features/auth/ui/LoginForm/LoginForm.tsx
+++ b/src/features/auth/ui/LoginForm/LoginForm.tsx
@@ -5,19 +5,19 @@ import { Input } from "@/entities/user/ui/Input/Input";
 import Button from "@/shared/ui/Button/Button";
 import { useAuthStore } from "../../model/auth.store";
 import { apiFetch } from "@/shared/api/fetcher";
+import { handleError } from "@/shared/error/errorHandler";
+import { AuthorizationError } from "@/shared/error/error";
 
 type FormSize = "sm" | "md" | "lg";
 
 interface LoginFormProps {
   size?: FormSize;
   onSuccess?: () => void;
-  onError?: (msg: string) => void;
 }
 
 export const LoginForm = ({
   size = "lg",
   onSuccess,
-  onError,
   ...props
 }: LoginFormProps) => {
   const [email, setEmail] = useState("");
@@ -44,8 +44,12 @@ export const LoginForm = ({
 
       setAccessToken(res.accessToken);
       onSuccess?.();
-    } catch {
-      onError?.("로그인에 실패하였습니다.\n이메일과 비밀번호를 확인해주세요.");
+    } catch (error) {
+      handleError(
+        new AuthorizationError(
+          "로그인에 실패하였습니다.\n이메일과 비밀번호를 확인해주세요.",
+        ),
+      );
     }
   };
 
diff --git a/src/features/auth/ui/SignUpForm/SignUpForm.stories.tsx b/src/features/auth/ui/SignUpForm/SignUpForm.stories.tsx
index 3b8d277e..8c3acf5b 100644
--- a/src/features/auth/ui/SignUpForm/SignUpForm.stories.tsx
+++ b/src/features/auth/ui/SignUpForm/SignUpForm.stories.tsx
@@ -9,7 +9,6 @@ const meta: Meta<typeof SignUpForm> = {
   },
   argTypes: {
     onSuccess: { action: "success" },
-    onError: { action: "error" },
   },
 };
 
diff --git a/src/features/auth/ui/SignUpForm/SignUpForm.tsx b/src/features/auth/ui/SignUpForm/SignUpForm.tsx
index 3a349e3c..d1c17662 100644
--- a/src/features/auth/ui/SignUpForm/SignUpForm.tsx
+++ b/src/features/auth/ui/SignUpForm/SignUpForm.tsx
@@ -6,13 +6,14 @@ import { DropDown } from "@/shared/ui/DropDown/DropDown";
 import Button from "@/shared/ui/Button/Button";
 import { apiFetch } from "@/shared/api/fetcher";
 import cn from "@/shared/lib/cn";
+import { handleError } from "@/shared/error/errorHandler";
+import { ServerError } from "@/shared/error/error";
 
 interface SignUpFormProps {
   onSuccess?: () => void;
-  onError?: (msg: string) => void;
 }
 
-export const SignUpForm = ({ onSuccess, onError }: SignUpFormProps) => {
+export const SignUpForm = ({ onSuccess }: SignUpFormProps) => {
   //input text 상태
   const [email, setEmail] = useState("");
   const [nickname, setNickname] = useState("");
@@ -149,7 +150,11 @@ export const SignUpForm = ({ onSuccess, onError }: SignUpFormProps) => {
         } else if (error.message.includes("NICKNAME_DUPLICATE")) {
           setNicknameError("이미 사용 중인 닉네임입니다.");
         } else {
-          onError?.("회원가입에 실패했습니다. 잠시 후 다시 시도해주세요.");
+          handleError(
+            new ServerError(
+              "회원가입 중 에러가 발생했습니다.\n잠시후 다시 시도해주세요.",
+            ),
+          );
         }
       }
     }
diff --git a/src/features/createPost/lib/usePostCreateModal.ts b/src/features/createPost/lib/usePostCreateModal.ts
index 7b71604f..63d5135f 100644
--- a/src/features/createPost/lib/usePostCreateModal.ts
+++ b/src/features/createPost/lib/usePostCreateModal.ts
@@ -24,17 +24,6 @@ export const usePostCreateModal = (handlers?: {
           });
         }, 100);
       },
-      onError: (message: string) => {
-        closeModal();
-
-        handlers?.onFailure?.();
-
-        openModal("normal", {
-          message: "게시물 등록 중 오류가 발생했습니다. " + message,
-          buttonText: "확인",
-          onClick: () => closeModal(),
-        });
-      },
     });
   };
 
diff --git a/src/features/createPost/ui/PostCreateModal/PostCreateModal.tsx b/src/features/createPost/ui/PostCreateModal/PostCreateModal.tsx
index 46529047..69960f3c 100644
--- a/src/features/createPost/ui/PostCreateModal/PostCreateModal.tsx
+++ b/src/features/createPost/ui/PostCreateModal/PostCreateModal.tsx
@@ -14,19 +14,18 @@ import "swiper/css/navigation";
 import "swiper/css/pagination";
 import { apiFetch } from "@/shared/api/fetcher";
 import { uploadImage } from "@/shared/api/uploadImage";
+import { handleError } from "@/shared/error/errorHandler";
 
 export interface PostCreateModalProps {
   className?: string;
   onClose?: () => void;
   onCreate?: () => void;
-  onError?: (message: string) => void;
 }
 
 export const PostCreateModal = ({
   className,
   onClose,
   onCreate,
-  onError,
 }: PostCreateModalProps) => {
   const [images, setImages] = useState<File[]>([]);
   const [title, setTitle] = useState("");
@@ -87,11 +86,7 @@ export const PostCreateModal = ({
       console.log("게시글 생성 성공! : ", res);
       onCreate?.();
     } catch (error) {
-      console.error("게시글 생성 실패 : ", error);
-      if (error instanceof Error) {
-        onError?.(error.message);
-      }
-      onError?.(String(error));
+      handleError(error, "게시글 생성 중 오류가 발생했습니다.");
     }
   };
 
diff --git a/src/features/editPost/ui/PostEditModal.tsx b/src/features/editPost/ui/PostEditModal.tsx
index fb87a357..ebfddaf2 100644
--- a/src/features/editPost/ui/PostEditModal.tsx
+++ b/src/features/editPost/ui/PostEditModal.tsx
@@ -14,6 +14,7 @@ import "swiper/css/navigation";
 import "swiper/css/pagination";
 import { apiFetch } from "@/shared/api/fetcher";
 import { uploadImage } from "@/shared/api/uploadImage";
+import { handleError } from "@/shared/error/errorHandler";
 
 const ImageSwiperSlide = (
   idx: number,
@@ -144,9 +145,7 @@ export const PostEditModal = ({
       console.log("게시글 수정 성공! : ", res);
       onEdit?.();
     } catch (error) {
-      console.error("게시글 수정 실패 : ", error);
-      const message = error instanceof Error ? error.message : String(error);
-      onError?.(message);
+      handleError(error, "게시글 수정 중 오류가 발생했습니다.");
     }
   };
 
diff --git a/src/features/editProfile/ui/ProfileEditModal/ProfileEditModal.tsx b/src/features/editProfile/ui/ProfileEditModal/ProfileEditModal.tsx
index 8988fcc9..b9f2e762 100644
--- a/src/features/editProfile/ui/ProfileEditModal/ProfileEditModal.tsx
+++ b/src/features/editProfile/ui/ProfileEditModal/ProfileEditModal.tsx
@@ -9,6 +9,7 @@ import { DropDown } from "@/shared/ui/DropDown/DropDown";
 import Button from "@/shared/ui/Button/Button";
 import { apiFetch } from "@/shared/api/fetcher";
 import { uploadImage } from "@/shared/api/uploadImage";
+import { handleError } from "@/shared/error/errorHandler";
 
 export interface ProfileEditModalProps {
   imageUrl?: string;
@@ -79,10 +80,7 @@ export const ProfileEditModal = ({
 
       onSave?.();
     } catch (error) {
-      if (error instanceof Error) {
-        console.error("프로필 수정 실패:", error);
-        onError?.(error);
-      } else onError?.(new Error(String(error)));
+      handleError(error, "프로필 수정 중 오류가 발생했습니다.");
     } finally {
       setLoading(false);
     }
diff --git a/src/shared/api/fetcher.ts b/src/shared/api/fetcher.ts
index 47632c48..2c0ee63c 100644
--- a/src/shared/api/fetcher.ts
+++ b/src/shared/api/fetcher.ts
@@ -1,6 +1,7 @@
 import { useAuthStore } from "@/features/auth/model/auth.store";
 import { refreshAccessToken } from "./refresh";
 import { useModalStore } from "@/shared/model/modal.store";
+import { AuthorizationError, NotFoundError, ServerError } from "../error/error";
 
 const BASE_URL = process.env.NEXT_PUBLIC_API_URL;
 
@@ -9,8 +10,7 @@ export async function apiFetch<T>(
   options: RequestInit & { noAuth?: boolean },
 ): Promise<T> {
   const { headers, noAuth, ...restOptions } = options;
-  const { accessToken, setAccessToken, logout } = useAuthStore.getState();
-  const { openModal, closeModal } = useModalStore.getState();
+  const { accessToken } = useAuthStore.getState();
 
   const defaultHeaders: HeadersInit = {
     "Content-Type": "application/json",
@@ -31,7 +31,11 @@ export async function apiFetch<T>(
   if (res.status === 401 && !noAuth) {
     const newToken = await refreshAccessToken();
 
-    if (!newToken) throw new Error("세션 만료");
+    if (!newToken)
+      throw new AuthorizationError(
+        "세션이 만료되었습니다.\n다시 로그인해주세요",
+        () => location.replace("/login"),
+      );
 
     defaultHeaders["Authorization"] = `Bearer ${newToken}`;
 
@@ -45,15 +49,23 @@ export async function apiFetch<T>(
   }
 
   if (!res.ok) {
-    let message = `API Error ${res.status}`;
-    try {
-      const data = await res.json();
-      message = data.message ?? data.detail ?? message;
-    } catch {
-      const text = await res.text();
-      if (text) message = text;
+    // 분기처리
+    if (res.status === 404) {
+      throw new NotFoundError("요청한 리소스를 찾을 수 없습니다.", () => {
+        location.replace("/");
+      });
     }
-    throw new Error(message);
+
+    if (res.status >= 500) {
+      throw new ServerError("서버 오류가 발생했습니다.", () => {
+        location.replace("/");
+      });
+    }
+
+    // 기타 오류 → 500 취급
+    throw new ServerError("알 수 없는 서버 오류", () => {
+      location.replace("/");
+    });
   }
 
   return res.json() as Promise<T>;
diff --git a/src/shared/api/refresh.ts b/src/shared/api/refresh.ts
index 4e3187b7..90324c4a 100644
--- a/src/shared/api/refresh.ts
+++ b/src/shared/api/refresh.ts
@@ -1,5 +1,6 @@
 import { useAuthStore } from "@/features/auth/model/auth.store";
 import { useModalStore } from "@/shared/model/modal.store";
+import { AuthorizationError } from "../error/error";
 
 const BASE_URL = process.env.NEXT_PUBLIC_API_URL;
 
@@ -12,17 +13,9 @@ export async function refreshAccessToken(): Promise<string | null> {
       method: "POST",
       credentials: "include",
     });
+    console.log(res);
 
     if (!res.ok) {
-      logout();
-      openModal("normal", {
-        message: "세션이 만료되었습니다. 다시 로그인 해주세요.",
-        buttonText: "확인",
-        onClick: () => {
-          closeModal();
-          location.replace("/login");
-        },
-      });
       return null;
     }
 
@@ -33,16 +26,11 @@ export async function refreshAccessToken(): Promise<string | null> {
 
     return newToken;
   } catch (err) {
-    logout();
-    openModal("normal", {
-      message: "세션이 만료되었습니다. 다시 로그인 해주세요.",
-      buttonText: "확인",
-      onClick: () => {
-        closeModal();
+    throw new AuthorizationError(
+      "세션이 만료되었습니다.\n다시 로그인 해주세요",
+      () => {
         location.replace("/login");
       },
-    });
-
-    return null;
+    );
   }
 }
diff --git a/src/shared/api/uploadImage.ts b/src/shared/api/uploadImage.ts
index 2284f315..9caa7f7b 100644
--- a/src/shared/api/uploadImage.ts
+++ b/src/shared/api/uploadImage.ts
@@ -1,3 +1,5 @@
+import { ServerError } from "../error/error";
+
 const BASE_URL = process.env.NEXT_PUBLIC_API_URL;
 
 export async function uploadImage(imageFile: File): Promise<string> {
@@ -20,17 +22,16 @@ export async function uploadImage(imageFile: File): Promise<string> {
         const text = await res.text();
         if (text) errorMessage = text;
       }
-      throw new Error(errorMessage);
+      throw new ServerError(errorMessage, () => location.replace("/"));
     }
 
     // 정상 응답 처리
     const data = await res.json();
     return data.imageUrl;
   } catch (err) {
-    console.error("이미지 업로드 중 오류 발생:", err);
-    if (err instanceof Error) {
-      throw new Error(err.message);
-    }
-    throw new Error("알 수 없는 오류가 발생했습니다.");
+    throw new ServerError(
+      "이미지 업로드 중 네트워크 오류가 발생했습니다.",
+      () => location.replace("/"),
+    );
   }
 }
diff --git a/src/shared/error/error.ts b/src/shared/error/error.ts
new file mode 100644
index 00000000..3a79b0b6
--- /dev/null
+++ b/src/shared/error/error.ts
@@ -0,0 +1,35 @@
+export class BaseError extends Error {
+  defaultMessage: string;
+  onConfirm?: () => void;
+
+  constructor(
+    defaultMessage: string,
+    message?: string,
+    onConfirm?: () => void,
+  ) {
+    super(message ?? defaultMessage);
+    this.name = this.constructor.name;
+    this.defaultMessage = defaultMessage;
+    this.onConfirm = onConfirm;
+  }
+}
+
+export class AuthorizationError extends BaseError {
+  constructor(message?: string, onConfirm?: () => void) {
+    super("인증이 필요합니다.", message, onConfirm);
+  }
+}
+
+export class NotFoundError extends BaseError {
+  resource?: string;
+
+  constructor(message?: string, onConfirm?: () => void) {
+    super("요청한 리소스를 찾을 수 없습니다.", message, onConfirm);
+  }
+}
+
+export class ServerError extends BaseError {
+  constructor(message?: string, onConfirm?: () => void) {
+    super("서버 오류가 발생했습니다.", message, onConfirm);
+  }
+}
diff --git a/src/shared/error/errorHandler.ts b/src/shared/error/errorHandler.ts
new file mode 100644
index 00000000..1899c483
--- /dev/null
+++ b/src/shared/error/errorHandler.ts
@@ -0,0 +1,21 @@
+import { useModalStore } from "../model/modal.store";
+import { BaseError } from "./error";
+
+export function handleError(error: unknown, context?: string) {
+  let message =
+    error instanceof BaseError
+      ? error.message
+      : "알 수 없는 오류가 발생했습니다.";
+  message = context ? `${context}\n${message}` : message;
+
+  const { openModal, closeModal } = useModalStore.getState();
+
+  console.error(error, context);
+  openModal("normal", {
+    message,
+    onClick: () => {
+      closeModal();
+      if (error instanceof BaseError) error.onConfirm?.();
+    },
+  });
+}
diff --git a/src/widgets/postDetail/ui/PostDetailSection.tsx b/src/widgets/postDetail/ui/PostDetailSection.tsx
index b4ca6217..b6263b3d 100644
--- a/src/widgets/postDetail/ui/PostDetailSection.tsx
+++ b/src/widgets/postDetail/ui/PostDetailSection.tsx
@@ -16,6 +16,7 @@ import { usePostEditModal } from "@/features/editPost/lib/usePostEditModal";
 import { useChatStore } from "@/features/chat/model/chat.store";
 import { useModalStore } from "@/shared/model/modal.store";
 import { PostDetail } from "@/entities/post/model/types/post";
+import { handleError } from "@/shared/error/errorHandler";
 
 export function PostDetailSection({ post }: { post: PostDetail }) {
   const router = useRouter();
@@ -76,7 +77,7 @@ export function PostDetailSection({ post }: { post: PostDetail }) {
             },
           });
         } catch (err) {
-          console.error("게시물 삭제 실패:", err);
+          handleError(err, "게시물 삭제 도중 오류가 발생했습니다.");
         }
       },
       onCancel: closeModal,