diff --git a/FbxExporter/Assets/UTJ/FbxExporter/Editor/FbxExporterWindow.cs b/FbxExporter/Assets/UTJ/FbxExporter/Editor/FbxExporterWindow.cs
index c477ee5..005beb4 100644
--- a/FbxExporter/Assets/UTJ/FbxExporter/Editor/FbxExporterWindow.cs
+++ b/FbxExporter/Assets/UTJ/FbxExporter/Editor/FbxExporterWindow.cs
@@ -1,3 +1,4 @@
+using System;
 using System.Linq;
 using System.Text.RegularExpressions;
 using System.Collections.Generic;
@@ -18,12 +19,20 @@ public static void Open()
             window.Show();
         }
 
-        enum Scope
+        public enum Scope
         {
             Selected,
             EntireScene,
         }
 
+        public class Record
+        {
+            public FbxExporter exporter;
+            public string path;
+            public DateTime started = DateTime.Now;
+        }
+        static List<Record> s_records = new List<Record>();
+
         Scope m_scope = Scope.Selected;
         bool m_includeChildren = true;
         FbxExporter.Format m_format = FbxExporter.Format.FbxBinary;
@@ -37,9 +46,35 @@ bool DoExport(string path, FbxExporter.Format format, GameObject[] objects)
             foreach (var obj in objects)
                 exporter.AddNode(obj);
 
-            var ret = exporter.Write(path, format);
-            exporter.Release();
-            return ret;
+            if(exporter.WriteAsync(path, format))
+            {
+                Debug.Log("Export started: " + path);
+                s_records.Add(new Record {path = path, exporter = exporter});
+                return true;
+            }
+            else
+            {
+                Debug.Log("Export failed: " + path);
+                return false;
+            }
+        }
+
+        void Update()
+        {
+            // poll async write
+            bool finished = false;
+            foreach (var record in s_records)
+            {
+                if (record.exporter.IsFinished())
+                {
+                    var elapsed = DateTime.Now - record.started;
+                    record.exporter.Release();
+                    Debug.Log("Export finished: " + record.path + " (" + elapsed.TotalSeconds + " seconds)");
+                    finished = true;
+                }
+            }
+            if (finished)
+                s_records.RemoveAll((a) => { return a.exporter.IsFinished(); });
         }
 
         void OnGUI()
diff --git a/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter.cs b/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter.cs
index 359b911..42da417 100644
--- a/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter.cs
+++ b/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter.cs
@@ -41,9 +41,14 @@ public void AddNode(GameObject go)
                 FindOrCreateNodeTree(go.GetComponent<Transform>(), ProcessNode);
         }
 
-        public bool Write(string path, Format format)
+        public bool WriteAsync(string path, Format format)
         {
-            return fbxeWrite(m_ctx, path, format);
+            return fbxeWriteAsync(m_ctx, path, format);
+        }
+
+        public bool IsFinished()
+        {
+            return fbxeIsFinished(m_ctx);
         }
 
 
diff --git a/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter_impl.cs b/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter_impl.cs
index 1e2afdb..ce13d71 100644
--- a/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter_impl.cs
+++ b/FbxExporter/Assets/UTJ/FbxExporter/Scripts/FbxExporter_impl.cs
@@ -77,7 +77,8 @@ public static ExportOptions defaultValue
         [DllImport("FbxExporterCore")] static extern void fbxeReleaseContext(Context ctx);
 
         [DllImport("FbxExporterCore")] static extern bool fbxeCreateScene(Context ctx, string name);
-        [DllImport("FbxExporterCore")] static extern bool fbxeWrite(Context ctx, string path, Format format);
+        [DllImport("FbxExporterCore")] static extern bool fbxeWriteAsync(Context ctx, string path, Format format);
+        [DllImport("FbxExporterCore")] static extern bool fbxeIsFinished(Context ctx);
 
         [DllImport("FbxExporterCore")] static extern Node fbxeGetRootNode(Context ctx);
         [DllImport("FbxExporterCore")] static extern Node fbxeFindNodeByName(Context ctx, string name);
diff --git a/Plugin/FbxExporter/FbxExporter.cpp b/Plugin/FbxExporter/FbxExporter.cpp
index 7d10d03..281b4c4 100644
--- a/Plugin/FbxExporter/FbxExporter.cpp
+++ b/Plugin/FbxExporter/FbxExporter.cpp
@@ -22,10 +22,16 @@ fbxeAPI int fbxeCreateScene(fbxe::IContext *ctx, const char *name)
     return ctx->createScene(name);
 }
 
-fbxeAPI int fbxeWrite(fbxe::IContext *ctx, const char *path, fbxe::Format format)
+fbxeAPI int fbxeWriteAsync(fbxe::IContext *ctx, const char *path, fbxe::Format format)
 {
     if (!ctx) { return false; }
-    return ctx->write(path, format);
+    return ctx->writeAsync(path, format);
+}
+
+fbxeAPI int fbxeIsFinished(fbxe::IContext *ctx)
+{
+    if (!ctx) { return false; }
+    return ctx->isFinished();
 }
 
 fbxeAPI fbxe::Node* fbxeGetRootNode(fbxe::IContext *ctx)
diff --git a/Plugin/FbxExporter/FbxExporter.h b/Plugin/FbxExporter/FbxExporter.h
index 8979d88..a223a0c 100644
--- a/Plugin/FbxExporter/FbxExporter.h
+++ b/Plugin/FbxExporter/FbxExporter.h
@@ -70,7 +70,8 @@ fbxeAPI fbxe::IContext* fbxeCreateContext(const fbxe::ExportOptions *opt);
 fbxeAPI void            fbxeReleaseContext(fbxe::IContext *ctx);
 
 fbxeAPI int         fbxeCreateScene(fbxe::IContext *ctx, const char *name);
-fbxeAPI int         fbxeWrite(fbxe::IContext *ctx, const char *path, fbxe::Format format);
+fbxeAPI int         fbxeWriteAsync(fbxe::IContext *ctx, const char *path, fbxe::Format format);
+fbxeAPI int         fbxeIsFinished(fbxe::IContext *ctx);
 
 fbxeAPI fbxe::Node* fbxeGetRootNode(fbxe::IContext *ctx);
 fbxeAPI fbxe::Node* fbxeFindNodeByName(fbxe::IContext *ctx, const char *name);
diff --git a/Plugin/FbxExporter/fbxeContext.cpp b/Plugin/FbxExporter/fbxeContext.cpp
index 4792576..774e446 100644
--- a/Plugin/FbxExporter/fbxeContext.cpp
+++ b/Plugin/FbxExporter/fbxeContext.cpp
@@ -72,7 +72,9 @@ class Context : public IContext
     void clear() override;
 
     bool createScene(const char *name) override;
-    bool write(const char *path, Format format) override;
+    bool writeAsync(const char *path, Format format) override;
+    bool isFinished() override;
+    void wait() override;
 
     Node* getRootNode() override;
     Node* findNodeByName(const char *name) override;
@@ -98,12 +100,12 @@ class Context : public IContext
 using ContextPtr = std::shared_ptr<Context>;
 
 
-static std::vector<ContextPtr> g_contexts;
+static std::map<void*, ContextPtr> g_contexts;
 
 fbxeAPI IContext* CreateContext(const ExportOptions *opt)
 {
     auto ret = new Context(opt);
-    g_contexts.emplace_back(ret);
+    g_contexts[ret].reset(ret);
     return ret;
 }
 
@@ -127,14 +129,12 @@ Context::~Context()
 
 void Context::release()
 {
-    // don't delete here to keep proceed async tasks
+    g_contexts.erase(this);
 }
 
 void Context::clear()
 {
-    if (m_task.valid()) {
-        m_task.wait();
-    }
+    wait();
     if (m_scene) {
         m_scene->Destroy(true);
         m_scene = nullptr;
@@ -160,26 +160,39 @@ bool Context::createScene(const char *name)
     return m_scene != nullptr;
 }
 
-bool Context::write(const char *path_, Format format)
+bool Context::writeAsync(const char *path_, Format format)
 {
     if (!m_scene) { return false; }
+    wait();
 
     std::string path = path_;
     m_task = std::async(std::launch::async, [this, path, format]() {
-        for (auto& p : m_mesh_data) {
-            for (auto& task : p.second->tasks) {
-                task();
-            }
-        }
-        m_mesh_data.clear();
-
         doWrite(path.c_str(), format);
     });
     return true;
 }
 
+bool Context::isFinished()
+{
+    return m_task.valid() && m_task.wait_for(std::chrono::milliseconds(0)) != std::future_status::timeout;
+}
+
+void Context::wait()
+{
+    if (m_task.valid()) {
+        m_task.wait();
+    }
+}
+
 bool Context::doWrite(const char *path, Format format)
 {
+    for (auto& p : m_mesh_data) {
+        for (auto& task : p.second->tasks) {
+            task();
+        }
+    }
+    m_mesh_data.clear();
+
     int file_format = 0;
     {
         // search file format index
diff --git a/Plugin/FbxExporter/fbxeContext.h b/Plugin/FbxExporter/fbxeContext.h
index b14efc7..ece8439 100644
--- a/Plugin/FbxExporter/fbxeContext.h
+++ b/Plugin/FbxExporter/fbxeContext.h
@@ -11,7 +11,9 @@ class IContext
     virtual void clear() = 0;
 
     virtual bool createScene(const char *name) = 0;
-    virtual bool write(const char *path, Format format = Format::FbxBinary) = 0;
+    virtual bool writeAsync(const char *path, Format format = Format::FbxBinary) = 0;
+    virtual bool isFinished() = 0;
+    virtual void wait() = 0;
 
     virtual Node* getRootNode() = 0;
     virtual Node* findNodeByName(const char *name) = 0;
diff --git a/Plugin/FbxExporter/pch.h b/Plugin/FbxExporter/pch.h
index 44af6bc..c8703e0 100644
--- a/Plugin/FbxExporter/pch.h
+++ b/Plugin/FbxExporter/pch.h
@@ -8,6 +8,7 @@
 #include <string>
 #include <vector>
 #include <map>
+#include <set>
 #include <functional>
 #include <memory>
 #include <iostream>
diff --git a/Plugin/Test/TestFbxExporter.cpp b/Plugin/Test/TestFbxExporter.cpp
index 9e79627..755c3ae 100644
--- a/Plugin/Test/TestFbxExporter.cpp
+++ b/Plugin/Test/TestFbxExporter.cpp
@@ -199,10 +199,10 @@ void TestFbxExportMesh()
         fbxeAddMeshSubmesh(ctx, mesh, fbxe::Topology::Quads, indices.size(), indices.data(), -1);
     }
 
-    fbxeWrite(ctx, "mesh_binary.fbx", fbxe::Format::FbxBinary);
-    fbxeWrite(ctx, "mesh_ascii.fbx", fbxe::Format::FbxAscii);
-    fbxeWrite(ctx, "mesh_encrypted.fbx", fbxe::Format::FbxEncrypted);
-    fbxeWrite(ctx, "mesh_obj.obj", fbxe::Format::Obj);
+    fbxeWriteAsync(ctx, "mesh_binary.fbx", fbxe::Format::FbxBinary);
+    fbxeWriteAsync(ctx, "mesh_ascii.fbx", fbxe::Format::FbxAscii);
+    fbxeWriteAsync(ctx, "mesh_encrypted.fbx", fbxe::Format::FbxEncrypted);
+    fbxeWriteAsync(ctx, "mesh_obj.obj", fbxe::Format::Obj);
     fbxeReleaseContext(ctx);
 }
 RegisterTestEntry(TestFbxExportMesh)
@@ -241,8 +241,8 @@ void TestFbxExportSkinnedMesh()
     fbxeAddMeshSubmesh(ctx, mesh, fbxe::Topology::Quads, indices.size(), indices.data(), -1);
     fbxeAddMeshSkin(ctx, mesh, weights.data(), num_bones, bones, bindposes);
 
-    fbxeWrite(ctx, "SkinnedMesh_binary.fbx", fbxe::Format::FbxBinary);
-    fbxeWrite(ctx, "SkinnedMesh_ascii.fbx", fbxe::Format::FbxAscii);
+    fbxeWriteAsync(ctx, "SkinnedMesh_binary.fbx", fbxe::Format::FbxBinary);
+    fbxeWriteAsync(ctx, "SkinnedMesh_ascii.fbx", fbxe::Format::FbxAscii);
     fbxeReleaseContext(ctx);
 }
 RegisterTestEntry(TestFbxExportSkinnedMesh)
@@ -299,8 +299,8 @@ void TestFbxExportSkinnedMeshSegmented()
         fbxeAddMeshSkin(ctx, mesh, weights.data(), num_bones, bones, bindposes);
     }
 
-    fbxeWrite(ctx, "SkinnedMeshSegmented_binary.fbx", fbxe::Format::FbxBinary);
-    fbxeWrite(ctx, "SkinnedMeshSegmented_ascii.fbx", fbxe::Format::FbxAscii);
+    fbxeWriteAsync(ctx, "SkinnedMeshSegmented_binary.fbx", fbxe::Format::FbxBinary);
+    fbxeWriteAsync(ctx, "SkinnedMeshSegmented_ascii.fbx", fbxe::Format::FbxAscii);
     fbxeReleaseContext(ctx);
 }
 RegisterTestEntry(TestFbxExportSkinnedMeshSegmented)
@@ -318,7 +318,7 @@ void TestFbxNameConflict()
     auto cnode11 = fbxeCreateNode(ctx, cnode2, "GrandChild $%&#?*@");
     auto cnode12 = fbxeCreateNode(ctx, cnode2, "GrandChild");
 
-    fbxeWrite(ctx, "namesanitize_ascii.fbx", fbxe::Format::FbxAscii);
+    fbxeWriteAsync(ctx, "namesanitize_ascii.fbx", fbxe::Format::FbxAscii);
     fbxeReleaseContext(ctx);
 }
 RegisterTestEntry(TestFbxNameConflict)
\ No newline at end of file