diff --git a/Qt5/timer/.gitignore b/Qt5/timer/.gitignore
new file mode 100644
index 0000000..96b2672
--- /dev/null
+++ b/Qt5/timer/.gitignore
@@ -0,0 +1,74 @@
+# This file is used to ignore files which are generated
+# ----------------------------------------------------------------------------
+
+*~
+*.autosave
+*.a
+*.core
+*.moc
+*.o
+*.obj
+*.orig
+*.rej
+*.so
+*.so.*
+*_pch.h.cpp
+*_resource.rc
+*.qm
+.#*
+*.*#
+core
+!core/
+tags
+.DS_Store
+.directory
+*.debug
+Makefile*
+*.prl
+*.app
+moc_*.cpp
+ui_*.h
+qrc_*.cpp
+Thumbs.db
+*.res
+*.rc
+/.qmake.cache
+/.qmake.stash
+
+# qtcreator generated files
+*.pro.user*
+CMakeLists.txt.user*
+
+# xemacs temporary files
+*.flc
+
+# Vim temporary files
+.*.swp
+
+# Visual Studio generated files
+*.ib_pdb_index
+*.idb
+*.ilk
+*.pdb
+*.sln
+*.suo
+*.vcproj
+*vcproj.*.*.user
+*.ncb
+*.sdf
+*.opensdf
+*.vcxproj
+*vcxproj.*
+
+# MinGW generated files
+*.Debug
+*.Release
+
+# Python byte code
+*.pyc
+
+# Binaries
+# --------
+*.dll
+*.exe
+
diff --git a/Qt5/timer/CMakeLists.txt b/Qt5/timer/CMakeLists.txt
new file mode 100644
index 0000000..9b24151
--- /dev/null
+++ b/Qt5/timer/CMakeLists.txt
@@ -0,0 +1,70 @@
+cmake_minimum_required(VERSION 3.5)
+
+project(timer VERSION 0.1 LANGUAGES CXX)
+
+set(CMAKE_AUTOUIC ON)
+set(CMAKE_AUTOMOC ON)
+set(CMAKE_AUTORCC ON)
+
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+
+find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Widgets)
+find_package(Qt${QT_VERSION_MAJOR} REQUIRED COMPONENTS Widgets)
+
+set(PROJECT_SOURCES
+        main.cpp
+        mainwindow.cpp
+        mainwindow.h
+        mainwindow.ui
+)
+
+if(${QT_VERSION_MAJOR} GREATER_EQUAL 6)
+    qt_add_executable(timer
+        MANUAL_FINALIZATION
+        ${PROJECT_SOURCES}
+    )
+# Define target properties for Android with Qt 6 as:
+#    set_property(TARGET timer APPEND PROPERTY QT_ANDROID_PACKAGE_SOURCE_DIR
+#                 ${CMAKE_CURRENT_SOURCE_DIR}/android)
+# For more information, see https://doc.qt.io/qt-6/qt-add-executable.html#target-creation
+else()
+    if(ANDROID)
+        add_library(timer SHARED
+            ${PROJECT_SOURCES}
+        )
+# Define properties for Android with Qt 5 after find_package() calls as:
+#    set(ANDROID_PACKAGE_SOURCE_DIR "${CMAKE_CURRENT_SOURCE_DIR}/android")
+    else()
+        add_executable(timer
+            ${PROJECT_SOURCES}
+        )
+    endif()
+endif()
+
+target_link_libraries(timer PRIVATE Qt${QT_VERSION_MAJOR}::Widgets)
+
+# Qt for iOS sets MACOSX_BUNDLE_GUI_IDENTIFIER automatically since Qt 6.1.
+# If you are developing for iOS or macOS you should consider setting an
+# explicit, fixed bundle identifier manually though.
+if(${QT_VERSION} VERSION_LESS 6.1.0)
+  set(BUNDLE_ID_OPTION MACOSX_BUNDLE_GUI_IDENTIFIER com.example.timer)
+endif()
+set_target_properties(timer PROPERTIES
+    ${BUNDLE_ID_OPTION}
+    MACOSX_BUNDLE_BUNDLE_VERSION ${PROJECT_VERSION}
+    MACOSX_BUNDLE_SHORT_VERSION_STRING ${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}
+    MACOSX_BUNDLE TRUE
+    WIN32_EXECUTABLE TRUE
+)
+
+include(GNUInstallDirs)
+install(TARGETS timer
+    BUNDLE DESTINATION .
+    LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
+    RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
+)
+
+if(QT_VERSION_MAJOR EQUAL 6)
+    qt_finalize_executable(timer)
+endif()
diff --git a/Qt5/timer/main.cpp b/Qt5/timer/main.cpp
new file mode 100644
index 0000000..aff48df
--- /dev/null
+++ b/Qt5/timer/main.cpp
@@ -0,0 +1,11 @@
+#include "mainwindow.h"
+
+#include <QApplication>
+
+int main(int argc, char *argv[])
+{
+    QApplication a(argc, argv);
+    MainWindow w;
+    w.show();
+    return a.exec();
+}
diff --git a/Qt5/timer/mainwindow.cpp b/Qt5/timer/mainwindow.cpp
new file mode 100644
index 0000000..0d03e8c
--- /dev/null
+++ b/Qt5/timer/mainwindow.cpp
@@ -0,0 +1,15 @@
+#include "mainwindow.h"
+#include "./ui_mainwindow.h"
+
+MainWindow::MainWindow(QWidget *parent)
+    : QMainWindow(parent)
+    , ui(new Ui::MainWindow)
+{
+    ui->setupUi(this);
+}
+
+MainWindow::~MainWindow()
+{
+    delete ui;
+}
+
diff --git a/Qt5/timer/mainwindow.h b/Qt5/timer/mainwindow.h
new file mode 100644
index 0000000..934b0f3
--- /dev/null
+++ b/Qt5/timer/mainwindow.h
@@ -0,0 +1,21 @@
+#ifndef MAINWINDOW_H
+#define MAINWINDOW_H
+
+#include <QMainWindow>
+
+QT_BEGIN_NAMESPACE
+namespace Ui { class MainWindow; }
+QT_END_NAMESPACE
+
+class MainWindow : public QMainWindow
+{
+    Q_OBJECT
+
+public:
+    MainWindow(QWidget *parent = nullptr);
+    ~MainWindow();
+
+private:
+    Ui::MainWindow *ui;
+};
+#endif // MAINWINDOW_H
diff --git a/Qt5/timer/mainwindow.ui b/Qt5/timer/mainwindow.ui
new file mode 100644
index 0000000..b742055
--- /dev/null
+++ b/Qt5/timer/mainwindow.ui
@@ -0,0 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>MainWindow</class>
+ <widget class="QMainWindow" name="MainWindow">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>800</width>
+    <height>600</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>MainWindow</string>
+  </property>
+  <widget class="QWidget" name="centralwidget"/>
+  <widget class="QMenuBar" name="menubar"/>
+  <widget class="QStatusBar" name="statusbar"/>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>