diff --git a/tests/test_item_use.rs b/tests/test_item_use.rs
new file mode 100644
index 0000000..a84afef
--- /dev/null
+++ b/tests/test_item_use.rs
@@ -0,0 +1,286 @@
+use elseware::common::serverstate::{ClientId, ServerState};
+use elseware::entity::gateway::{EntityGateway, InMemoryGateway};
+use elseware::entity::item;
+use elseware::ship::ship::{ShipServerState, RecvShipPacket};
+//use elseware::ship::items::{ClientItemId, ActiveItemEntityId, HeldItemType, FloorItemType};
+
+use libpso::packet::ship::*;
+use libpso::packet::messages::*;
+
+#[path = "common.rs"]
+mod common;
+use common::*;
+
+
+#[async_std::test]
+async fn test_use_monomate() {
+    let mut entity_gateway = InMemoryGateway::new();
+
+    let (_user1, char1) = new_user_character(&mut entity_gateway, "a1", "a").await;
+
+    for (slot, tool) in vec![item::tool::ToolType::Monomate, item::tool::ToolType::Monofluid].into_iter().enumerate() {
+        for _ in 0..2 {
+            entity_gateway.create_item(
+                item::NewItemEntity {
+                    item: item::ItemDetail::Tool(
+                        item::tool::Tool {
+                            tool: tool
+                        }
+                    ),
+                    location: item::ItemLocation::Inventory {
+                        character_id: char1.id,
+                        slot: slot,
+                        equipped: false,
+                    }
+                }).await;
+        }
+    }
+
+    let mut ship = ShipServerState::new(entity_gateway.clone());
+    log_in_char(&mut ship, ClientId(1), "a1", "a").await;
+    join_lobby(&mut ship, ClientId(1)).await;
+    create_room(&mut ship, ClientId(1), "room", "").await;
+
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10000,
+    })))).await.unwrap().for_each(drop);
+
+    let items = entity_gateway.get_items_by_character(&char1).await;
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::Monomate
+        }
+        else {
+            false
+        }
+    }).count() == 1);
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::Monofluid
+        }
+        else {
+            false
+        }
+    }).count() == 2);
+}
+
+#[async_std::test]
+async fn test_use_monomate_twice() {
+    let mut entity_gateway = InMemoryGateway::new();
+
+    let (_user1, char1) = new_user_character(&mut entity_gateway, "a1", "a").await;
+
+    for (slot, tool) in vec![item::tool::ToolType::Monomate, item::tool::ToolType::Monofluid].into_iter().enumerate() {
+        for _ in 0..3 {
+            entity_gateway.create_item(
+                item::NewItemEntity {
+                    item: item::ItemDetail::Tool(
+                        item::tool::Tool {
+                            tool: tool
+                        }
+                    ),
+                    location: item::ItemLocation::Inventory {
+                        character_id: char1.id,
+                        slot: slot,
+                        equipped: false,
+                    }
+                }).await;
+        }
+    }
+
+    let mut ship = ShipServerState::new(entity_gateway.clone());
+    log_in_char(&mut ship, ClientId(1), "a1", "a").await;
+    join_lobby(&mut ship, ClientId(1)).await;
+    create_room(&mut ship, ClientId(1), "room", "").await;
+
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10000,
+    })))).await.unwrap().for_each(drop);
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10000,
+    })))).await.unwrap().for_each(drop);
+
+    let items = entity_gateway.get_items_by_character(&char1).await;
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::Monomate
+        }
+        else {
+            false
+        }
+    }).count() == 1);
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::Monofluid
+        }
+        else {
+            false
+        }
+    }).count() == 3);
+}
+
+#[async_std::test]
+async fn test_use_last_monomate() {
+    let mut entity_gateway = InMemoryGateway::new();
+
+    let (_user1, char1) = new_user_character(&mut entity_gateway, "a1", "a").await;
+
+    for (slot, tool) in vec![item::tool::ToolType::Monomate, item::tool::ToolType::Monofluid].into_iter().enumerate() {
+        for _ in 0..1 {
+            entity_gateway.create_item(
+                item::NewItemEntity {
+                    item: item::ItemDetail::Tool(
+                        item::tool::Tool {
+                            tool: tool
+                        }
+                    ),
+                    location: item::ItemLocation::Inventory {
+                        character_id: char1.id,
+                        slot: slot,
+                        equipped: false,
+                    }
+                }).await;
+        }
+    }
+
+    let mut ship = ShipServerState::new(entity_gateway.clone());
+    log_in_char(&mut ship, ClientId(1), "a1", "a").await;
+    join_lobby(&mut ship, ClientId(1)).await;
+    create_room(&mut ship, ClientId(1), "room", "").await;
+
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10000,
+    })))).await.unwrap().for_each(drop);
+
+    let items = entity_gateway.get_items_by_character(&char1).await;
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::Monomate
+        }
+        else {
+            false
+        }
+    }).count() == 0);
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::Monofluid
+        }
+        else {
+            false
+        }
+    }).count() == 1);
+}
+
+#[async_std::test]
+async fn test_use_nonstackable_tool() {
+    let mut entity_gateway = InMemoryGateway::new();
+
+    let (_user1, char1) = new_user_character(&mut entity_gateway, "a1", "a").await;
+
+    entity_gateway.create_item(
+        item::NewItemEntity {
+            item: item::ItemDetail::Tool(
+                item::tool::Tool {
+                    tool: item::tool::ToolType::MagicStoneIritista,
+                }
+            ),
+            location: item::ItemLocation::Inventory {
+                character_id: char1.id,
+                slot: 0,
+                equipped: false,
+            }
+        }).await;
+
+    let mut ship = ShipServerState::new(entity_gateway.clone());
+    log_in_char(&mut ship, ClientId(1), "a1", "a").await;
+    join_lobby(&mut ship, ClientId(1)).await;
+    create_room(&mut ship, ClientId(1), "room", "").await;
+
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10000,
+    })))).await.unwrap().for_each(drop);
+
+    let items = entity_gateway.get_items_by_character(&char1).await;
+    assert!(items.len() == 0);
+}
+
+#[async_std::test]
+async fn test_use_materials() {
+    let mut entity_gateway = InMemoryGateway::new();
+
+    let (user1, char1) = new_user_character(&mut entity_gateway, "a1", "a").await;
+
+    for (slot, tool) in vec![item::tool::ToolType::PowerMaterial, item::tool::ToolType::LuckMaterial].into_iter().enumerate() {
+        for _ in 0..5 {
+            entity_gateway.create_item(
+                item::NewItemEntity {
+                    item: item::ItemDetail::Tool(
+                        item::tool::Tool {
+                            tool: tool
+                        }
+                    ),
+                    location: item::ItemLocation::Inventory {
+                        character_id: char1.id,
+                        slot: slot,
+                        equipped: false,
+                    }
+                }).await;
+        }
+    }
+
+    let mut ship = ShipServerState::new(entity_gateway.clone());
+    log_in_char(&mut ship, ClientId(1), "a1", "a").await;
+    join_lobby(&mut ship, ClientId(1)).await;
+    create_room(&mut ship, ClientId(1), "room", "").await;
+
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10000,
+    })))).await.unwrap().for_each(drop);
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10001,
+    })))).await.unwrap().for_each(drop);
+    ship.handle(ClientId(1), &RecvShipPacket::Message(Message::new(GameMessage::PlayerUseItem(PlayerUseItem {
+        client: 0,
+        target: 0,
+        item_id: 0x10001,
+    })))).await.unwrap().for_each(drop);
+
+    let items = entity_gateway.get_items_by_character(&char1).await;
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::PowerMaterial
+        }
+        else {
+            false
+        }
+    }).count() == 4);
+    assert!(items.iter().filter(|item| {
+        if let item::ItemDetail::Tool(t) = item.item {
+            t.tool == item::tool::ToolType::LuckMaterial
+        }
+        else {
+            false
+        }
+    }).count() == 3);
+
+    let characters = entity_gateway.get_characters_by_user(&user1).await;
+    let char = characters[0].as_ref().unwrap();
+
+    assert!(char.materials.power == 1);
+    assert!(char.materials.luck == 2);
+}
+