diff --git a/Assets/UniGLTF/Runtime/UniGLTF/IO/glbImporter.cs b/Assets/UniGLTF/Runtime/UniGLTF/IO/glbImporter.cs
index d6415a0de..a0d489672 100644
--- a/Assets/UniGLTF/Runtime/UniGLTF/IO/glbImporter.cs
+++ b/Assets/UniGLTF/Runtime/UniGLTF/IO/glbImporter.cs
@@ -48,27 +48,33 @@ namespace UniGLTF
 
         public static List<GlbChunk> ParseGlbChunks(Byte[] bytes)
         {
-            if (bytes.Length == 0)
+            //
+            // glb header(12byte)
+            //
+            if (bytes.Length < 12)
             {
-                throw new Exception("empty bytes");
+                throw new FormatException("not glb header");
             }
 
             int pos = 0;
             if (Encoding.ASCII.GetString(bytes, 0, 4) != GLB_MAGIC)
             {
-                throw new Exception("invalid magic");
+                throw new FormatException("invalid magic");
             }
             pos += 4;
 
             var version = BitConverter.ToUInt32(bytes, pos);
             if (version != GLB_VERSION)
             {
-                Debug.LogWarningFormat("unknown version: {0}", version);
-                return null;
+                throw new FormatException($"unknown version: {version}");
             }
             pos += 4;
 
-            //var totalLength = BitConverter.ToUInt32(bytes, pos);
+            var totalLength = BitConverter.ToUInt32(bytes, pos);
+            if (bytes.Length < totalLength)
+            {
+                throw new System.IO.EndOfStreamException($"Not enough size: {bytes.Length} < {totalLength}");
+            }
             pos += 4;
 
             var chunks = new List<GlbChunk>();
diff --git a/Assets/UniGLTF/Tests/UniGLTF/GlbParserTests.cs b/Assets/UniGLTF/Tests/UniGLTF/GlbParserTests.cs
index 02de02b20..ae99dba8c 100644
--- a/Assets/UniGLTF/Tests/UniGLTF/GlbParserTests.cs
+++ b/Assets/UniGLTF/Tests/UniGLTF/GlbParserTests.cs
@@ -63,16 +63,14 @@ namespace UniGLTF
             var bytes = File.ReadAllBytes(path);
             var data = new GlbBinaryParser(bytes, Path.GetFileNameWithoutExtension(path)).Parse();
 
-            // ２個目のチャンクを削る
+            // glb header + 1st chunk only
             var mod = bytes.Take(12 + 8 + data.Chunks[0].Bytes.Count).ToArray();
-            // 再パース
 
-            Assert.Throws<IOException>(() =>
+            Assert.Throws<EndOfStreamException>(() =>
             {
+                // 再パース
                 var data2 = new GlbBinaryParser(mod, Path.GetFileNameWithoutExtension(path)).Parse();
             });
-
-            var a = 0;
         }
     }
 }