diff --git a/composer.json b/composer.json
index b531f1f..5bff9c6 100644
--- a/composer.json
+++ b/composer.json
@@ -31,7 +31,6 @@
         "ext-simplexml": "*",
         "ext-intl": "*",
         "ext-mbstring": "*",
-        "monolog/monolog": "*"
     },
     "require-dev" : {
         "phpunit/phpunit": "^7",
diff --git a/lib/Ogone/AbstractRequest.php b/lib/Ogone/AbstractRequest.php
index 8d2ef79..c9b44db 100644
--- a/lib/Ogone/AbstractRequest.php
+++ b/lib/Ogone/AbstractRequest.php
@@ -11,7 +11,8 @@
 namespace Ogone;
 
 use InvalidArgumentException;
-use Psr\Log\LoggerInterface;
+use Ogone\Logger\AdapterInterface;
+use Ogone\Logger\MonologAdapter;
 use RuntimeException;
 use BadMethodCallException;
 use Ogone\ShaComposer\ShaComposer;
@@ -158,11 +159,9 @@ abstract class AbstractRequest implements Request
 
     protected $parameters = array();
 
-    /** @var LoggerInterface|null */
+    /** @var Logger */
     protected $logger;
 
-
-
     protected $ogoneFields = array(
         'orig', 'shoppingcartextensionid', 'pspid', 'orderid', 'com', 'amount', 'currency', 'language', 'cn', 'email',
         'cardno', 'cvc', 'ed', 'ownerzip', 'owneraddress', 'ownercty', 'ownertown', 'ownertelno',
@@ -233,13 +232,26 @@ abstract class AbstractRequest implements Request
     /**
      * Sets Logger.
      *
-     * @param LoggerInterface|null $logger
+     * @param AdapterInterface $logger
      *
      * @return $this
+     * @throws \Exception
      */
-    public function setLogger(LoggerInterface $logger = null)
+    public function setLogger($logger)
     {
-        $this->logger = $logger;
+        if (interface_exists('\Psr\Log\LoggerInterface') &&
+            $logger instanceof \Psr\Log\LoggerInterface
+        ) {
+            $this->logger = new Logger(
+                new MonologAdapter(['logger' => $logger])
+            );
+        }
+
+        if (!$logger instanceof AdapterInterface) {
+            throw new \Exception('Argument $logger must be instance of AdapterInterface.');
+        }
+
+        $this->logger = new Logger($logger);
 
         return $this;
     }
diff --git a/lib/Ogone/AbstractResponse.php b/lib/Ogone/AbstractResponse.php
index 9341692..de29845 100644
--- a/lib/Ogone/AbstractResponse.php
+++ b/lib/Ogone/AbstractResponse.php
@@ -11,7 +11,8 @@
 namespace Ogone;
 
 use InvalidArgumentException;
-use Psr\Log\LoggerInterface;
+use Ogone\Logger\AdapterInterface;
+use Ogone\Logger\MonologAdapter;
 
 abstract class AbstractResponse implements Response, \ArrayAccess
 {
@@ -100,7 +101,7 @@ abstract class AbstractResponse implements Response, \ArrayAccess
      */
     protected $shaSign;
 
-    /** @var LoggerInterface|null */
+    /** @var Logger */
     protected $logger;
 
     /**
@@ -127,13 +128,26 @@ public function __construct(array $httpRequest)
     /**
      * Sets Logger.
      *
-     * @param LoggerInterface|null $logger
+     * @param AdapterInterface $logger
      *
      * @return $this
+     * @throws \Exception
      */
-    public function setLogger(LoggerInterface $logger = null)
+    public function setLogger($logger)
     {
-        $this->logger = $logger;
+        if (interface_exists('\Psr\Log\LoggerInterface') &&
+            $logger instanceof \Psr\Log\LoggerInterface
+        ) {
+            $this->logger = new Logger(
+                new MonologAdapter(['logger' => $logger])
+            );
+        }
+
+        if (!$logger instanceof AdapterInterface) {
+            throw new \Exception('Argument $logger must be instance of AdapterInterface.');
+        }
+
+        $this->logger = new Logger($logger);
 
         return $this;
     }
diff --git a/lib/Ogone/Logger.php b/lib/Ogone/Logger.php
new file mode 100644
index 0000000..97cd65f
--- /dev/null
+++ b/lib/Ogone/Logger.php
@@ -0,0 +1,130 @@
+<?php
+
+namespace Ogone;
+
+use Ogone\Logger\AdapterInterface;
+
+class Logger
+{
+    const EMERGENCY = 'emergency';
+    const ALERT     = 'alert';
+    const CRITICAL  = 'critical';
+    const ERROR     = 'error';
+    const WARNING   = 'warning';
+    const NOTICE    = 'notice';
+    const INFO      = 'info';
+    const DEBUG     = 'debug';
+
+    /**
+     * @var AdapterInterface
+     */
+    private $adapter;
+
+    /**
+     * @param AdapterInterface $adapter
+     */
+    public function __construct(AdapterInterface $adapter)
+    {
+        $this->adapter = $adapter;
+    }
+
+    /**
+     * Logs with emergency level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function emergency($message, array $context = [])
+    {
+        $this->log(self::EMERGENCY, $message, $context);
+    }
+
+    /**
+     * Logs with error level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function alert($message, array $context = [])
+    {
+        $this->log(self::ALERT, $message, $context);
+    }
+
+    /**
+     * Logs with critical level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function critical($message, array $context = [])
+    {
+        $this->log(self::CRITICAL, $message, $context);
+    }
+
+    /**
+     * Logs with error level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function error($message, array $context = [])
+    {
+        $this->log(self::ERROR, $message, $context);
+    }
+
+    /**
+     * Logs with warning level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function warning($message, array $context = [])
+    {
+        $this->log(self::WARNING, $message, $context);
+    }
+
+    /**
+     * Logs with notice level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function notice($message, array $context = [])
+    {
+        $this->log(self::NOTICE, $message, $context);
+    }
+
+    /**
+     * Logs with info level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function info($message, array $context = [])
+    {
+        $this->log(self::INFO, $message, $context);
+    }
+
+    /**
+     * Logs with debug level.
+     *
+     * @param string $message
+     * @param array $context
+     */
+    public function debug($message, array $context = [])
+    {
+        $this->log(self::DEBUG, $message, $context);
+    }
+
+    /**
+     * Logs with an arbitrary level.
+     *
+     * @param mixed $level
+     * @param string $message
+     * @param array $context
+     */
+    public function log($level, $message, array $context = [])
+    {
+        $this->adapter->log($level, $message, $context);
+    }
+}
diff --git a/lib/Ogone/Logger/AdapterInterface.php b/lib/Ogone/Logger/AdapterInterface.php
new file mode 100644
index 0000000..959decf
--- /dev/null
+++ b/lib/Ogone/Logger/AdapterInterface.php
@@ -0,0 +1,15 @@
+<?php
+
+namespace Ogone\Logger;
+
+interface AdapterInterface
+{
+    /**
+     * Logs with an arbitrary level.
+     *
+     * @param mixed $level
+     * @param string $message
+     * @param array $context
+     */
+    public function log($level, $message, array $context = []);
+}
diff --git a/lib/Ogone/Logger/FileAdapter.php b/lib/Ogone/Logger/FileAdapter.php
new file mode 100644
index 0000000..f15a769
--- /dev/null
+++ b/lib/Ogone/Logger/FileAdapter.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace Ogone\Logger;
+
+class FileAdapter implements AdapterInterface
+{
+    private $file;
+
+    /**
+     * Constructor.
+     *
+     * @param array $options
+     */
+    public function __construct(array $options)
+    {
+        if (isset($options['file'])) {
+            $this->file = $options['file'];
+        } else {
+            $this->file = sys_get_temp_dir() . '/ingenico_sdk.log';
+        }
+    }
+
+    /**
+     * Logs with an arbitrary level.
+     *
+     * @param mixed $level
+     * @param string $message
+     * @param array $context
+     */
+    public function log($level, $message, array $context = [])
+    {
+        if ($this->file) {
+            $message = sprintf(
+                '[%s] %s %s %s',
+                date('Y-m-d H:i:s'),
+                $level,
+                $message,
+                count($context) > 0 ? var_export($context, true) : ''
+            );
+
+            file_put_contents($this->file, $message . "\n", FILE_APPEND);
+        }
+    }
+}
diff --git a/lib/Ogone/Logger/MonologAdapter.php b/lib/Ogone/Logger/MonologAdapter.php
new file mode 100644
index 0000000..d5e8b48
--- /dev/null
+++ b/lib/Ogone/Logger/MonologAdapter.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace Ogone\Logger;
+
+class MonologAdapter implements AdapterInterface
+{
+    /**
+     * @var \Monolog\Logger|\Psr\Log\LoggerInterface
+     */
+    private $logger;
+
+    /**
+     * Constructor.
+     *
+     * @param array $options
+     */
+    public function __construct(array $options)
+    {
+        if (isset($options['logger'])) {
+            $this->logger = $options['logger'];
+        }
+    }
+
+    /**
+     * Logs with an arbitrary level.
+     *
+     * @param mixed $level
+     * @param string $message
+     * @param array $context
+     */
+    public function log($level, $message, array $context = [])
+    {
+        if ($this->logger) {
+            $this->logger->log($level, $message, $context);
+        }
+    }
+}
\ No newline at end of file
diff --git a/tests/Ogone/Tests/AbstractRequestTest.php b/tests/Ogone/Tests/AbstractRequestTest.php
new file mode 100644
index 0000000..9dbe22a
--- /dev/null
+++ b/tests/Ogone/Tests/AbstractRequestTest.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Ogone\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Ogone\Ecommerce\EcommercePaymentRequest;
+use Ogone\Logger\FileAdapter;
+
+class AbstractRequestTest extends TestCase
+{
+    public function testSetLogger()
+    {
+        //$request = new EcommercePaymentRequest();
+        //new FileAdapter(['file' => sys_get_temp_dir() . '/log.txt']);
+    }
+}
\ No newline at end of file
diff --git a/tests/Ogone/Tests/Logger/FileAdapterTest.php b/tests/Ogone/Tests/Logger/FileAdapterTest.php
new file mode 100644
index 0000000..266bd04
--- /dev/null
+++ b/tests/Ogone/Tests/Logger/FileAdapterTest.php
@@ -0,0 +1,22 @@
+<?php
+
+namespace Ogone\Tests\Logger;
+
+use PHPUnit\Framework\TestCase;
+use Ogone\Logger;
+use Ogone\Logger\AdapterInterface;
+use Ogone\Logger\FileAdapter;
+
+class FileAdapterTest extends TestCase
+{
+    public function testLogAdapter()
+    {
+        $logFile = sys_get_temp_dir() . '/ingenico_sdk.log';
+
+        $adapter = new FileAdapter(['file' => $logFile]);
+        $this->assertInstanceOf(AdapterInterface::class, $adapter);
+
+        $adapter->log(Logger::INFO, 'Test');
+        $this->assertEquals(true, file_exists($logFile));
+    }
+}
diff --git a/tests/Ogone/Tests/Logger/MonologAdapterTest.php b/tests/Ogone/Tests/Logger/MonologAdapterTest.php
new file mode 100644
index 0000000..ee2856c
--- /dev/null
+++ b/tests/Ogone/Tests/Logger/MonologAdapterTest.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Ogone\Tests\Logger;
+
+use Ogone\Logger;
+use PHPUnit\Framework\TestCase;
+use Ogone\Logger\AdapterInterface;
+use Ogone\Logger\MonologAdapter;
+
+class MonologAdapterTest extends TestCase
+{
+    public function testLogAdapter()
+    {
+        $adapter = new MonologAdapter(['logger' => null]);
+        $this->assertInstanceOf(AdapterInterface::class, $adapter);
+        $this->assertNull($adapter->log(Logger::INFO, 'Test'));
+    }
+}
diff --git a/tests/Ogone/Tests/LoggerTest.php b/tests/Ogone/Tests/LoggerTest.php
new file mode 100644
index 0000000..94873e8
--- /dev/null
+++ b/tests/Ogone/Tests/LoggerTest.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace Ogone\Tests;
+
+use PHPUnit\Framework\TestCase;
+use Ogone\Logger;
+use Ogone\Logger\FileAdapter;
+
+class LoggerTest extends TestCase
+{
+    public function testLog()
+    {
+        $logFile = sys_get_temp_dir() . '/ingenico_sdk.log';
+
+        $adapter = new FileAdapter(['file' => $logFile]);
+        $logger = new Logger($adapter);
+
+        $logger->log($logger::INFO, 'Test');
+        $this->assertEquals(true, file_exists($logFile));
+
+        $logger->emergency('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::EMERGENCY) !== false);
+
+        $logger->alert('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::ALERT) !== false);
+
+        $logger->critical('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::CRITICAL) !== false);
+
+        $logger->error('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::ERROR) !== false);
+
+        $logger->warning('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::WARNING) !== false);
+
+        $logger->notice('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::NOTICE) !== false);
+
+        $logger->info('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::INFO) !== false);
+
+        $logger->debug('Test');
+        $this->assertEquals(true, stripos(file_get_contents($logFile), $logger::DEBUG) !== false);
+
+        return $this;
+    }
+}
\ No newline at end of file