diff --git a/modules/twainui/Manager.cpp b/modules/twainui/Manager.cpp
index fa107c40..46d0fd46 100644
--- a/modules/twainui/Manager.cpp
+++ b/modules/twainui/Manager.cpp
@@ -5,6 +5,14 @@
 
 Manager::Manager()
     : QObject(nullptr)
+    , m_progressUiCallback(std::function<void(ui_result)>())
+    , m_notify(nullptr)
+    , m_settingUiCallback(std::function<void(ui_result)>())
+    , m_deviceSelectUi(nullptr)
+    , m_settingUi(nullptr)
+    , m_progressUi(nullptr)
+    , m_msgBoxUi(nullptr)
+    , m_twainSrcUi(nullptr)
 {
     HGBase_CreateEvent(HGFALSE, HGFALSE, &m_event);
 
@@ -27,6 +35,51 @@ Manager::~Manager()
     HGBase_DestroyEvent(m_event);
 }
 
+void Manager::closeDeviceSelectUi()
+{
+    if (m_deviceSelectUi != nullptr)
+    {
+        delete m_deviceSelectUi;
+        m_deviceSelectUi = nullptr;
+    }
+}
+
+void Manager::closeSettingUi()
+{
+    if (m_settingUi != nullptr)
+    {
+        delete m_settingUi;
+        m_settingUi = nullptr;
+    }
+}
+
+void Manager::closeProgressUi()
+{
+    if (m_progressUi != nullptr)
+    {
+        delete m_progressUi;
+        m_progressUi = nullptr;
+    }
+}
+
+void Manager::closeMessageBoxUi()
+{
+    if (m_msgBoxUi != nullptr)
+    {
+        delete m_msgBoxUi;
+        m_msgBoxUi = nullptr;
+    }
+}
+
+void Manager::closeTwainSrcUi()
+{
+    if (m_twainSrcUi != nullptr)
+    {
+        delete m_twainSrcUi;
+        m_twainSrcUi = nullptr;
+    }
+}
+
 int Manager::showDeviceSelect(bool qt, const std::vector<DEVQUEUI>& devs)
 {
     m_DeviceSelectDevs = devs;
@@ -151,9 +204,10 @@ void Manager::on_init()
 
 void Manager::on_createDeviceSelect(bool qt)
 {
-    Dialog_device_select dlg(m_DeviceSelectDevs);
-    dlg.exec();
-    m_DeviceSelectResult = dlg.getDevId();
+    if (m_deviceSelectUi != nullptr)
+        m_deviceSelectUi = new Dialog_device_select(m_DeviceSelectDevs);
+    m_deviceSelectUi->exec();
+    m_DeviceSelectResult = m_deviceSelectUi->getDevId();
 
     if (!qt)
     {
@@ -175,9 +229,10 @@ void Manager::on_createSettingUi(bool qt)
     qParent = m_settingUiParent;
 #endif
 
-    hg_settingdialog *dlg = new hg_settingdialog(m_device, &m_api, m_with_scan, m_devName.c_str(), m_settingUiCallback, qParent);
-    dlg->setModal(true);
-    dlg->show();
+    if (m_settingUi != nullptr)
+        m_settingUi = new hg_settingdialog(m_device, &m_api, m_with_scan, m_devName.c_str(), m_settingUiCallback, qParent);
+    m_settingUi->setModal(true);
+    m_settingUi->show();
 }
 
 void Manager::on_createProgressUi(bool qt)
@@ -195,9 +250,10 @@ void Manager::on_createProgressUi(bool qt)
     qParent = m_progressUiparent;
 #endif
 
-    Dialog_progress_ui *dlg = new Dialog_progress_ui(m_progressUiCallback, m_notify, qParent);
-    dlg->setModal(true);
-    dlg->show();
+    if (m_progressUi != nullptr)
+        m_progressUi = new Dialog_progress_ui(m_progressUiCallback, m_notify, qParent);
+    m_progressUi->setModal(true);
+    m_progressUi->show();
 
     if (!qt)
     {
@@ -219,10 +275,11 @@ void Manager::on_createMessageBoxUi(bool qt)
     qParent = m_messageBoxUiParent;
 #endif
 
-    QMessageBox *msg = new QMessageBox(QMessageBox::Critical, tr("Prompt"), QString::fromStdString(m_message), QMessageBox::Ok, qParent);
-    msg->setWindowFlags(Qt::SubWindow | Qt::Popup | Qt::WindowStaysOnTopHint);
-    msg->setModal(true);
-    msg->show();
+    if (m_msgBoxUi != nullptr)
+        m_msgBoxUi = new QMessageBox(QMessageBox::Critical, tr("Prompt"), QString::fromStdString(m_message), QMessageBox::Ok, qParent);
+    m_msgBoxUi->setWindowFlags(Qt::SubWindow | Qt::Popup | Qt::WindowStaysOnTopHint);
+    m_msgBoxUi->setModal(true);
+    m_msgBoxUi->show();
 }
 
 void Manager::on_createTwainSrcUi(bool qt)
@@ -239,10 +296,11 @@ void Manager::on_createTwainSrcUi(bool qt)
     qParent = m_TwainSrcUiparent;
 #endif
 
-    Dialog_Twain_Source_Select dlg(m_dsmProc, &m_appId, qParent);
-    if (dlg.exec())
+    if (m_twainSrcUi != nullptr)
+        m_twainSrcUi = new Dialog_Twain_Source_Select (m_dsmProc, &m_appId, qParent);
+    if (m_twainSrcUi->exec())
     {
-        dlg.GetIdentify(&m_ds);
+        m_twainSrcUi->GetIdentify(&m_ds);
     }
 
     if (!qt)
diff --git a/modules/twainui/Manager.h b/modules/twainui/Manager.h
index ca0cc781..ecc1880f 100644
--- a/modules/twainui/Manager.h
+++ b/modules/twainui/Manager.h
@@ -15,6 +15,12 @@ public:
     Manager();
     ~Manager();
 
+    void closeDeviceSelectUi();
+    void closeSettingUi();
+    void closeProgressUi();
+    void closeMessageBoxUi();
+    void closeTwainSrcUi();
+
     int showDeviceSelect(bool qt, const std::vector<DEVQUEUI>& devs);
     int showSettingUi(bool qt, SANE_Handle device, HWND settingUiParent, LPSANEAPI api, const char *devName, bool with_scan, std::function<void(ui_result)> callback);
     int showProgressUi(bool qt, HWND parent, std::function<void (ui_result)> callback, std::function<void (int, void *, int)> *notify);
@@ -44,10 +50,12 @@ private:
 
     HGEvent m_event;
 
+    Dialog_device_select *m_deviceSelectUi;
     std::vector<DEVQUEUI> m_DeviceSelectDevs;
     unsigned long m_DeviceSelectThreadId;
     int m_DeviceSelectResult;
 
+    hg_settingdialog *m_settingUi;
     unsigned long m_SettingUiThreadId;
     SANE_Handle m_device;
     HWND m_settingUiParent;
@@ -56,17 +64,20 @@ private:
     bool m_with_scan;
     std::function<void(ui_result)> m_settingUiCallback;
 
+    Dialog_progress_ui *m_progressUi;
     HWND m_progressUiparent;
     unsigned long m_ProgressUiThreadId;
     std::function<void (ui_result)> m_progressUiCallback;
     std::function<void (int, void *, int)> *m_notify;
 
+    QMessageBox *m_msgBoxUi;
     unsigned long m_MessageBoxUiThreadId;
     HWND m_messageBoxUiParent;
     int m_notifyEvent;
     std::string m_message;
     int m_flag;
 
+    Dialog_Twain_Source_Select *m_twainSrcUi;
     unsigned long m_twainSrcUiThreadId;
     DSMENTRYPROC m_dsmProc;
     TW_IDENTITY m_appId;
diff --git a/modules/twainui/twainui.cpp b/modules/twainui/twainui.cpp
index 1129f9cb..e7788b04 100644
--- a/modules/twainui/twainui.cpp
+++ b/modules/twainui/twainui.cpp
@@ -173,3 +173,26 @@ int show_twain_srclist_ui(DSMENTRYPROC dsmProc, const TW_IDENTITY *appId, HGWind
 
     return g_manager->showTwainSrcUi(nullptr == g_hThread, dsmProc, appId, parent, ds);
 }
+
+int close_ui(int which)
+{
+    if (NULL == g_manager)
+    {
+        return 0;
+    }
+
+    if (UI_INDICATOR == which)
+    {
+        g_manager->closeProgressUi();
+    }
+    else if (UI_SETTING == which)
+    {
+        g_manager->closeSettingUi();
+    }
+    else if (UI_MSG_BOX == which)
+    {
+        g_manager->closeMessageBoxUi();
+    }
+
+    return 0;
+}