diff --git a/src/main/java/org/ntlab/acanthus_server/entities/Animation.java b/src/main/java/org/ntlab/acanthus_server/entities/Animation.java
index 42f0cd6..109b7d4 100644
--- a/src/main/java/org/ntlab/acanthus_server/entities/Animation.java
+++ b/src/main/java/org/ntlab/acanthus_server/entities/Animation.java
@@ -12,6 +12,7 @@
 import org.ntlab.acanthus_server.entities.Position;
 import org.ntlab.acanthus_server.entities.Stroke;
 
+import java.lang.reflect.Array;
 import java.time.LocalDateTime;
 import java.time.format.DateTimeFormatter;
 import java.util.ArrayList;
@@ -38,7 +39,7 @@
     @JsonProperty("hashTag")
     private ArrayList<String> hashTag = new ArrayList<>();
     @JsonProperty("pageMap")
-    private HashMap<Integer, Page> pageMap = new HashMap<>();
+    private ArrayList<Page> pageMap = new ArrayList<>();
     @JsonIgnore
     private Account owner;
     @JsonIgnore
@@ -62,7 +63,7 @@
         this.isPublic = false;
         this.owner = owner;
         this.editors.add(new Editor(owner, true));
-        this.pageMap.put(0, new Page(1));
+        this.pageMap.add(new Page(0, 1));
         this.lastUpdate = date.format(dateTimeFormatter);
     }
 
@@ -97,10 +98,6 @@
         this.lastUpdate = dt.toString();
     }
 
-    public void setPageMap(int pid, Page page) {
-        this.pageMap.put(pid, page);
-    }
-
     //-----------------------------------------------------------------
     // add
 
@@ -151,8 +148,8 @@
         return lastUpdate;
     }
 
-    public HashMap<Integer, Page> getPageMap() {
-        return pageMap;
+    public ArrayList<Page> getPages() {
+        return this.pageMap;
     }
 
     //-----------------------------------------------------------------
@@ -217,7 +214,7 @@
         this.isPublic = false;
         this.owner = ownerAccount;
         this.editors.add(new Editor(owner, true));
-        this.pageMap.put(0, new Page(1));
+        this.pageMap.add(new Page(0, 1));
 
         LocalDateTime date = LocalDateTime.now();
         DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofPattern("yyyy/MM/dd HH:mm:ss");
diff --git a/src/main/java/org/ntlab/acanthus_server/entities/Page.java b/src/main/java/org/ntlab/acanthus_server/entities/Page.java
index 45e276f..4c3869f 100644
--- a/src/main/java/org/ntlab/acanthus_server/entities/Page.java
+++ b/src/main/java/org/ntlab/acanthus_server/entities/Page.java
@@ -1,16 +1,23 @@
 package org.ntlab.acanthus_server.entities;
 
+import com.fasterxml.jackson.annotation.JsonProperty;
+
 import java.util.ArrayList;
 
 public class Page {
+    @JsonProperty("pid")
+    private Integer pid;
+    @JsonProperty("pageNo")
     private Integer pageNo;
+    @JsonProperty("layers")
     private ArrayList<Layer> layers = new ArrayList<>();
 
     // _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
     // _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
-    public Page(Integer pageNo) {
+    public Page(Integer pid, Integer pageNo) {
         var maxLayer = 4;
         for (int i = 0; i < maxLayer; i++) this.layers.add(new Layer());
+        this.pid = pid;
         this.pageNo = pageNo;
     }
 
@@ -24,6 +31,10 @@
         return pageNo;
     }
 
+    public Integer getPid() {
+        return pid;
+    }
+
     // _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
     // setter
     public void setLayers(ArrayList<Layer> layers) {
diff --git a/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java b/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java
index d6d451e..88b550c 100644
--- a/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java
+++ b/src/main/java/org/ntlab/acanthus_server/resources/gallery/LayersRest.java
@@ -26,7 +26,7 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Integer getLayers(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         return pages.get(pid).getLayers().size();
     }
 
@@ -40,7 +40,7 @@
     @POST
     @Produces(MediaType.APPLICATION_JSON)
     public Integer addLayer(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
 
         if (pages.get(pid).getLayers().size() < 4) {
             pages.get(pid).getLayers().add(new Layer());
@@ -60,7 +60,7 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Integer getStrokeNo(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid, @PathParam("layerNo") Integer layerNo) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();
 
         if (strokes == null) return null;
diff --git a/src/main/java/org/ntlab/acanthus_server/resources/gallery/PagesRest.java b/src/main/java/org/ntlab/acanthus_server/resources/gallery/PagesRest.java
index e415b33..bfdeec8 100644
--- a/src/main/java/org/ntlab/acanthus_server/resources/gallery/PagesRest.java
+++ b/src/main/java/org/ntlab/acanthus_server/resources/gallery/PagesRest.java
@@ -28,7 +28,7 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public Collection<Page> getPages(@PathParam("aid") Integer aid) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap().values();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         return pages;
     }
 
@@ -45,12 +45,12 @@
         var maxSize = 999;
 
         //最大値以上はページを追加させない
-        if (animation.getPageMap().size() < maxSize) {
-            var newPage = new Page(animation.getPageMap().size() + 1);
-            animation.setPageMap(new Random().nextInt(), newPage);
+        if (animation.getPages().size() < maxSize) {
+            var newPage = new Page(new Random().nextInt(), animation.getPages().size() + 1);
+            animation.getPages().add(newPage);
         }
 
-        return animation.getPageMap().size();
+        return animation.getPages().size();
     }
 
 
@@ -61,16 +61,28 @@
     public Integer getPageSize(@PathParam("aid") Integer aid) {
         var animation = gallery.getAnimationByAid(aid);
 
-        return animation.getPageMap().size();
+        return animation.getPages().size();
     }
 
+    // _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
+    @Path("/{aid}/pageMap/{pageNo}")
+    @GET
+    @Produces(MediaType.APPLICATION_JSON)
+    public Integer getPageId(@PathParam("aid") Integer aid, @PathParam("pageNo") Integer pageNo) {
+        var animation = gallery.getAnimationByAid(aid);
+        for (var page : animation.getPages()) {
+            if (page.getPageNo().equals(pageNo)) return page.getPid();
+        }
+
+        throw new WebApplicationException(404);
+    }
 
     // _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
-    @Path("/{aid}/pageMap/{pid}")
+    @Path("/{aid}/pageMap/{pageNo}")
     @DELETE
     @Produces(MediaType.APPLICATION_JSON)
-    public Integer deletePage(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+    public Integer deletePage(@PathParam("aid") Integer aid, @PathParam("pageNo") Integer pageNo) {
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var response = Response.status(Response.Status.NO_CONTENT);
 
         if (pages.size() <= 1) {
@@ -78,15 +90,15 @@
             throw new WebApplicationException(response.build());
         }
 
-        var removedPageNo = pages.get(pid).getPageNo().intValue();
-        pages.remove(pid);
+        // 一致するページ番号を取得して削除
+        for (int i = 0; i < pages.size(); i++) {
+            if (pageNo.equals(pages.get(i).getPageNo())) pages.remove(i);
+        }
 
         // _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
         // 削除してページ番号をソートしなおす
-
-        for (var page : pages.values()) {
-            var pageNo = page.getPageNo();
-            if (removedPageNo < pageNo) page.setPageNo(pageNo - 1);
+        for (var page : pages) {
+            if (pageNo < page.getPageNo()) page.setPageNo(page.getPageNo() - 1);
         }
 
         return pages.size();
diff --git a/src/main/java/org/ntlab/acanthus_server/resources/gallery/StrokesRest.java b/src/main/java/org/ntlab/acanthus_server/resources/gallery/StrokesRest.java
index c198b52..a196653 100644
--- a/src/main/java/org/ntlab/acanthus_server/resources/gallery/StrokesRest.java
+++ b/src/main/java/org/ntlab/acanthus_server/resources/gallery/StrokesRest.java
@@ -29,7 +29,7 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public ArrayList<Stroke> getStrokes(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid, @PathParam("layerNo") Integer layerNo) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         return pages.get(pid).getLayers().get(layerNo).getStrokes();
     }
 
@@ -52,7 +52,7 @@
     public String addStrokes(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid, @PathParam("layerNo") Integer layerNo,
                               @FormParam("uid") Integer uid, @FormParam("strokeNo") Integer strokeNo, @FormParam("uidToken") String uidToken, @FormParam("pen") Integer pen,
                               @FormParam("color") Integer color, @FormParam("thick") Integer thick) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();
 
         Stroke stroke = new Stroke();
@@ -86,7 +86,7 @@
     @DELETE
     @Produces(MediaType.APPLICATION_JSON)
     public String deleteStrokes(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid, @PathParam("layerNo") Integer layerNo, @QueryParam("uid") Integer uid) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();
 
         strokes.clear();
@@ -111,7 +111,7 @@
     @Produces(MediaType.APPLICATION_JSON)
     public String deleteStrokeByStrokeNo(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid,
                                  @PathParam("layerNo") Integer layerNo, @PathParam("strokeNo") Integer strokeNo) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();
 
         strokes.remove((int) strokeNo);
@@ -135,7 +135,7 @@
     @Produces(MediaType.APPLICATION_JSON)
     public SortedSet<Position> getPositions(@PathParam("aid") Integer aid, @PathParam("pid") Integer pid,
                                             @PathParam("layerNo") Integer layerNo, @PathParam("strokeNo") Integer strokeNo) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();
 
 /*        Collections.sort(strokes.get(strokeNo).getPositions(), new Comparator() {
@@ -168,7 +168,7 @@
     @Produces(MediaType.APPLICATION_JSON)
     public String addPosition(@FormParam("positionNo") Integer positionNo, @PathParam("aid") Integer aid, @PathParam("pid") Integer pid, @PathParam("strokeNo") Integer strokeNo,
                                 @PathParam("layerNo") Integer layerNo, @FormParam("x") Float x, @FormParam("y") Float y) {
-        var pages = gallery.getAnimationByAid(aid).getPageMap();
+        var pages = gallery.getAnimationByAid(aid).getPages();
         var strokes = pages.get(pid).getLayers().get(layerNo).getStrokes();