diff --git a/src/main.py b/src/main.py
index d12529a..07d11f4 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,3 +1,4 @@
+import logging
 import os
 from shlex import join
 from tempfile import TemporaryDirectory
@@ -8,13 +9,18 @@ import discord_tools.message
 import discord_tools.pixiv_link_extractor
 import pixiv.pixiv_api as pixiv_api
 
+logging.basicConfig(
+    format="[%(asctime)s] [%(levelname)8s] %(name)s: %(message)s", level=logging.INFO
+)
+
+
 REFRESH_TOKEN = os.getenv("PIXIV_REFRESH_TOKEN")
 if REFRESH_TOKEN is None:
-    print("Pixiv refresh token is missing, please set PIXIV_REFRESH_TOKEN")
+    logging.fatal("Pixiv refresh token is missing, please set PIXIV_REFRESH_TOKEN")
     exit(1)
 DISCORD_TOKEN = os.getenv("DISCORD_TOKEN")
 if DISCORD_TOKEN is None:
-    print("Discord token is missing, please set DISCORD_TOKEN")
+    logging.fatal("Discord token is missing, please set DISCORD_TOKEN")
     exit(1)
 
 
@@ -36,7 +42,7 @@ client = MyClient(intents=intents)
 
 @client.event
 async def on_ready():
-    print(f"We have logged in as {client.user}")
+    logging.info(f"We have logged in as {client.user}")
 
 
 @client.tree.command()
@@ -106,7 +112,7 @@ async def pixiv_preview(interaction: discord.Interaction, message: discord.Messa
 
 @client.event
 async def on_guild_join(guild: discord.Guild):
-    print(f"Joined new guild: {guild.name}")
+    logging.info(f"Joined new guild: {guild.name}")
 
 
 @client.event
diff --git a/src/pixiv/pixiv_api.py b/src/pixiv/pixiv_api.py
index 46bc8f4..bed34e1 100644
--- a/src/pixiv/pixiv_api.py
+++ b/src/pixiv/pixiv_api.py
@@ -1,3 +1,4 @@
+import logging
 import os
 import threading
 from queue import Queue
@@ -24,13 +25,13 @@ def dowload_pixiv_images(
         return None
     pages = illust["meta_pages"]
     if len(pages) > 0:
-        print(f"Dowloading mutiple images to {dest_folder} ({len(pages)})")
+        logging.info(f"Dowloading mutiple images to {dest_folder} ({len(pages)})")
         if max_thread_num > len(pages):
             num_threads = len(pages)
         else:
             num_threads = max_thread_num
-            
-        print(f"Starting {num_threads} thread(s)")
+
+        logging.info(f"Starting {num_threads} thread(s)")
         workers: List[Thread] = []
         q: Queue[Union[Tuple[str, str, pixivpy3.AppPixivAPI], None]] = Queue()
         for i in range(num_threads):
@@ -53,11 +54,11 @@ def dowload_pixiv_images(
             worker.join()
 
     else:
-        print(f"Dowloading single image to {dest_folder}")
+        logging.info(f"Dowloading single image to {dest_folder}")
         api.download(
             url=illust["meta_single_page"]["original_image_url"], path=dest_folder
         )
-    print("Download finished !")
+    logging.info("Download finished !")
     return illust["title"]
 
 
@@ -66,11 +67,11 @@ def download_thread(q: Queue[Union[Tuple[str, str, pixivpy3.AppPixivAPI], None]]
     while True:
         data = q.get()
         if data is None:
-            print(f"[{thread_name}] - Bye bye")
+            logging.debug(f"[{thread_name}] - Bye bye")
             q.task_done()
             break
         (url, dest_folder, api) = data
-        print(f"[{thread_name}] - Downloading {url}...")
+        logging.debug(f"[{thread_name}] - Downloading {url}...")
         api.download(url=url, path=dest_folder)
-        print(f"[{thread_name}] - ... Done")
+        logging.debug(f"[{thread_name}] - ... Done")
         q.task_done()