diff --git a/src/main/java/jp/riken/neurodata/tools/BioFormatsImageInfo.java b/src/main/java/jp/riken/neurodata/tools/BioFormatsImageInfo.java
index 632262b..d922c4f 100644
--- a/src/main/java/jp/riken/neurodata/tools/BioFormatsImageInfo.java
+++ b/src/main/java/jp/riken/neurodata/tools/BioFormatsImageInfo.java
@@ -271,8 +271,8 @@ public class BioFormatsImageInfo {
         results.put("status", status);
         results.put("message", message);
         results.put("format", format);
-        results.put("thumbnail", thumbnail.isEmpty() ? null : thumbnail);
         results.put("metadata", metadata.isEmpty() ? null : metadata);
+        results.put("thumbnail", thumbnail.isEmpty() ? null : thumbnail);
         System.out.println(getJsonString(results));
 
         if (!status) {
diff --git a/src/main/java/jp/riken/neurodata/tools/BioFormatsImageThumbnail.java b/src/main/java/jp/riken/neurodata/tools/BioFormatsImageThumbnail.java
index 1ab6e5e..7c0f880 100644
--- a/src/main/java/jp/riken/neurodata/tools/BioFormatsImageThumbnail.java
+++ b/src/main/java/jp/riken/neurodata/tools/BioFormatsImageThumbnail.java
@@ -149,12 +149,21 @@ public class BioFormatsImageThumbnail {
             throw new BioFormatsImageException("unsupported file: " + path);
         }
         try {
-            final int series = 0;
+            int series = 0;
+            final int seriesCount = reader.getSeriesCount();
+            for (int i = 0; i < seriesCount; i++) {
+                reader.setSeries(i);
+                if (reader.isThumbnailSeries()) {
+                    series = i;
+                    break;
+                }
+            }
+            reader.setSeries(series);
             final int no = 0;
-            // System.out.println("series count: " + reader.getSeriesCount());
+            // System.out.println("series count: " + seriesCount);
             // System.out.println("image count: " + reader.getImageCount());
             // System.out.println("resolution: " + reader.getResolutionCount());
-            reader.setSeries(series);
+            // System.out.println("thubmail series: " + series);
             ret = reader.openThumbImage(no);
         } catch (final Throwable e) {
             for (Throwable t = e; t != null; t = t.getCause()) {