diff --git a/src/lib/utils/appl.h b/src/lib/utils/appl.h
index 35d9657d..80894c9f 100644
--- a/src/lib/utils/appl.h
+++ b/src/lib/utils/appl.h
@@ -76,7 +76,7 @@ class Appl
 
 public:
 	/**
-	 * @brief create an Appl instance and return the reference.
+	 * @brief create an appl instance and return the reference.
 	 * @param command is true if an command is needed.
 	 * @return the reference to instance.
 	 */
diff --git a/src/lib/utils/thread.cpp b/src/lib/utils/thread.cpp
index fa4ca38f..4ea84136 100644
--- a/src/lib/utils/thread.cpp
+++ b/src/lib/utils/thread.cpp
@@ -23,9 +23,13 @@
 
 #include "thread.h"
 
+/**
+ * @brief static function which will be called on thread startup.
+ * @return void pointer.
+ */
 static void* runThread(void* arg)
 {
-	return ((Thread *)arg)->run();
+	return ((Thread*)arg)->run();
 }
 
 Thread::~Thread()
diff --git a/src/lib/utils/thread.h b/src/lib/utils/thread.h
index 03ecfd0d..4d4e15dc 100644
--- a/src/lib/utils/thread.h
+++ b/src/lib/utils/thread.h
@@ -22,23 +22,60 @@
 
 #include <pthread.h>
 
+/**
+ * @brief wrapper class for pthread.
+ */
 class Thread
 {
 
 public:
+	/**
+	 * @brief constructor.
+	 */
 	Thread() : m_threadid(0), m_running(false), m_detached(false) {}
+
+	/**
+	 * @brief virtual destructor.
+	 */
 	virtual ~Thread();
 
+	/**
+	 * @brief create the thread and set name for process list.
+	 * @param name the thread name which show in process list.
+	 * @return value of thread creating.
+	 */
 	int start(const char* name);
+
+	/**
+	 * @brief join the thread.
+	 * @return value of thread joining.
+	 */
 	int join();
+
+	/**
+	 * @brief detach the thread.
+	 * @return value of thread detaching.
+	 */
 	int detach();
+
+	/**
+	 * @brief return the thread id.
+	 * @return own thread id.
+	 */
 	pthread_t self() {return m_threadid; }
 
+	/**
+	 * @brief virtul function which must be implented in derived class.
+	 * @return void pointer.
+	 */
 	virtual void* run() = 0;
 
 private:
+	/** own thread id */
 	pthread_t m_threadid;
+	/** true if thread is running */
 	bool m_running;
+	/** true if thread is detached */
 	bool m_detached;
 
 };