diff --git a/wCenterWindow/CLogger.cpp b/wCenterWindow/CLogger.cpp
new file mode 100644
index 0000000..33bb49c
--- /dev/null
+++ b/wCenterWindow/CLogger.cpp
@@ -0,0 +1,78 @@
+// wCenterWindow
+// CLogger.cpp
+#include "CLogger.h"
+#include <filesystem>
+
+inline wchar_t* CLogger::GetTimeStamp() {
+	GetLocalTime(&lt);
+	swprintf_s(logTimeBuffer, L"%d-%02d-%02d %02d:%02d:%02d.%03d | ", lt.wYear, lt.wMonth, lt.wDay, lt.wHour, lt.wMinute, lt.wSecond, lt.wMilliseconds);
+	return logTimeBuffer;
+}
+
+void CLogger::Out(const wchar_t* fmt, ...) {
+	if (fsLogFile.is_open()) {
+		va_list args;
+		va_start(args, fmt);
+		EnterCriticalSection(&cs);
+		_vsnwprintf_s(logBuffer, _countof(logBuffer), _TRUNCATE, fmt, args);
+		va_end(args);
+		fsLogFile << GetTimeStamp() << logBuffer << std::endl;
+		LeaveCriticalSection(&cs);
+	}
+}
+
+void CLogger::Init() {
+	InitializeCriticalSection(&cs);
+	wchar_t szPath[MAX_PATH] = { 0 };
+	DWORD dwPathLength = GetModuleFileNameW(NULL, szPath, MAX_PATH);
+	DWORD dwError = GetLastError();
+	if (ERROR_INSUFFICIENT_BUFFER == dwError) {
+		MessageBoxW(NULL, L"Warning!\nPath to log file is too long! Working without logging.", szAppTitle.c_str(), MB_OK | MB_ICONWARNING);
+		return;
+	}
+	if (NULL == dwPathLength) {
+		MessageBoxW(NULL, L"Warning!\nCan't get application's filename! Working without logging.", szAppTitle.c_str(), MB_OK | MB_ICONWARNING);
+		return;
+	}
+
+	std::filesystem::path log_path = szPath;
+	log_path.replace_extension(L".log");
+	std::filesystem::path bak_path = log_path;
+	bak_path.replace_extension(L".bak");
+
+	if (std::filesystem::exists(log_path)) std::filesystem::rename(log_path, bak_path);
+#ifdef _DEBUG
+	log_path = L"D:\\test.log";
+#endif
+	fsLogFile.open(log_path, std::ios::trunc);
+	if (fsLogFile.is_open()) {
+		fsLogFile << "\xEF\xBB\xBF";																// (0xEF, 0xBB, 0xBF) - UTF-8 BOM
+		fsLogFile.imbue(std::locale("en-US.utf8"));
+		fsLogFile << GetTimeStamp() << "[ " << szAppTitleVer.c_str() << " ] Start log." << std::endl;
+		fsLogFile << GetTimeStamp() << "Logfile: \"" << log_path.native() << "\"" << std::endl;
+	}
+	else {
+		MessageBoxW(NULL, L"Warning!\nCan't create log file! Working without logging.", szAppTitle.c_str(), MB_OK | MB_ICONWARNING);
+	}
+}
+
+CLogger::CLogger(const wchar_t* _appTitle) {
+	szAppTitle = _appTitle;
+	szAppTitleVer = _appTitle;
+	Init();
+}
+
+CLogger::CLogger(const wchar_t* _appTitle, const wchar_t* _appVersion) {
+	szAppTitle = _appTitle; szAppVersion = _appVersion;
+	szAppTitleVer = _appTitle;
+	szAppTitleVer.append(L", v").append(_appVersion);
+	Init();
+}
+
+CLogger::~CLogger() {
+	if (fsLogFile) {
+		fsLogFile << GetTimeStamp() << "Stop log." << std::endl;
+		fsLogFile.close();
+		DeleteCriticalSection(&cs);
+	}
+}
diff --git a/wCenterWindow/CLogger.h b/wCenterWindow/CLogger.h
new file mode 100644
index 0000000..0f6bd33
--- /dev/null
+++ b/wCenterWindow/CLogger.h
@@ -0,0 +1,31 @@
+// wCenterWindow
+// CLogger.h
+#pragma once
+#include <Windows.h>
+#include <fstream>
+
+#define MAX_LOGBUFFER_LENGTH 512
+
+class CLogger
+{
+public:
+	void Out(const wchar_t*, ...);
+	CLogger(const wchar_t*);
+	CLogger(const wchar_t*, const wchar_t*);
+	~CLogger();
+
+private:
+	SYSTEMTIME lt;
+	CRITICAL_SECTION cs;
+	HANDLE hLoggerThread = NULL;
+	HANDLE hLoggerEvent = NULL;
+	wchar_t logTimeBuffer[28]{ 0 };
+	wchar_t logBuffer[MAX_LOGBUFFER_LENGTH]{ 0 };
+	std::wofstream fsLogFile;
+	std::wstring szAppTitle{ 0 };
+	std::wstring szAppVersion{ 0 };
+	std::wstring szAppTitleVer{ 0 };
+
+	inline wchar_t* GetTimeStamp();
+	void Init();
+};