diff --git a/.devcontainer/Dockerfile b/.devcontainer/Dockerfile
index c6644d40..cbc48896 100644
--- a/.devcontainer/Dockerfile
+++ b/.devcontainer/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.10.14-slim-bullseye
+FROM python:3.12.8-slim-bullseye
 
 ARG PIP_DEFAULT_TIMEOUT=100 \
     PIP_DISABLE_PIP_VERSION_CHECK=on \
diff --git a/.tool-versions b/.tool-versions
index dd816d9f..e0dcae3b 100644
--- a/.tool-versions
+++ b/.tool-versions
@@ -1,2 +1,2 @@
-python 3.10.14
+python 3.12.8
 poetry 1.8.5
diff --git a/poetry.lock b/poetry.lock
index 5b5e45f4..6479e1df 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -23,10 +23,8 @@ files = [
 ]
 
 [package.dependencies]
-exceptiongroup = {version = ">=1.0.2", markers = "python_version < \"3.11\""}
 idna = ">=2.8"
 sniffio = ">=1.1"
-typing-extensions = {version = ">=4.1", markers = "python_version < \"3.11\""}
 
 [package.extras]
 doc = ["Sphinx (>=7.4,<8.0)", "packaging", "sphinx-autodoc-typehints (>=1.2.0)", "sphinx-rtd-theme"]
@@ -341,9 +339,6 @@ files = [
     {file = "coverage-7.6.8.tar.gz", hash = "sha256:8b2b8503edb06822c86d82fa64a4a5cb0760bb8f31f26e138ec743f422f37cfc"},
 ]
 
-[package.dependencies]
-tomli = {version = "*", optional = true, markers = "python_full_version <= \"3.11.0a6\" and extra == \"toml\""}
-
 [package.extras]
 toml = ["tomli"]
 
@@ -403,20 +398,6 @@ typing-extensions = ">=3.7.4.1"
 all = ["pytz (>=2019.1)"]
 dates = ["pytz (>=2019.1)"]
 
-[[package]]
-name = "exceptiongroup"
-version = "1.2.2"
-description = "Backport of PEP 654 (exception groups)"
-optional = false
-python-versions = ">=3.7"
-files = [
-    {file = "exceptiongroup-1.2.2-py3-none-any.whl", hash = "sha256:3111b9d131c238bec2f8f516e123e14ba243563fb135d3fe885990585aa7795b"},
-    {file = "exceptiongroup-1.2.2.tar.gz", hash = "sha256:47c2edf7c6738fafb49fd34290706d1a1a2f4d1c6df275526b62cbb4aa5393cc"},
-]
-
-[package.extras]
-test = ["pytest (>=6)"]
-
 [[package]]
 name = "filelock"
 version = "3.16.1"
@@ -671,7 +652,6 @@ files = [
 
 [package.dependencies]
 mypy-extensions = ">=1.0.0"
-tomli = {version = ">=1.1.0", markers = "python_version < \"3.11\""}
 typing-extensions = ">=4.6.0"
 
 [package.extras]
@@ -846,7 +826,6 @@ files = [
 
 [package.dependencies]
 packaging = ">=24.1"
-tomli = {version = ">=2.0.1", markers = "python_version < \"3.11\""}
 
 [package.extras]
 docs = ["furo (>=2024.8.6)", "sphinx-autodoc-typehints (>=2.4.1)"]
@@ -865,11 +844,9 @@ files = [
 
 [package.dependencies]
 colorama = {version = "*", markers = "sys_platform == \"win32\""}
-exceptiongroup = {version = ">=1.0.0rc8", markers = "python_version < \"3.11\""}
 iniconfig = "*"
 packaging = "*"
 pluggy = ">=1.5,<2"
-tomli = {version = ">=1", markers = "python_version < \"3.11\""}
 
 [package.extras]
 dev = ["argcomplete", "attrs (>=19.2)", "hypothesis (>=3.56)", "mock", "pygments (>=2.7.2)", "requests", "setuptools", "xmlschema"]
@@ -1113,7 +1090,6 @@ sphinxcontrib-htmlhelp = ">=2.0.6"
 sphinxcontrib-jsmath = ">=1.0.1"
 sphinxcontrib-qthelp = ">=1.0.6"
 sphinxcontrib-serializinghtml = ">=1.1.9"
-tomli = {version = ">=2", markers = "python_version < \"3.11\""}
 
 [package.extras]
 docs = ["sphinxcontrib-websupport"]
@@ -1363,8 +1339,6 @@ packaging = ">=24.1"
 platformdirs = ">=4.3.6"
 pluggy = ">=1.5"
 pyproject-api = ">=1.8"
-tomli = {version = ">=2.0.1", markers = "python_version < \"3.11\""}
-typing-extensions = {version = ">=4.12.2", markers = "python_version < \"3.11\""}
 virtualenv = ">=20.26.6"
 
 [package.extras]
@@ -1454,7 +1428,6 @@ files = [
 [package.dependencies]
 click = ">=7.0"
 h11 = ">=0.8"
-typing-extensions = {version = ">=4.0", markers = "python_version < \"3.11\""}
 
 [package.extras]
 standard = ["colorama (>=0.4)", "httptools (>=0.6.3)", "python-dotenv (>=0.13)", "pyyaml (>=5.1)", "uvloop (>=0.14.0,!=0.15.0,!=0.15.1)", "watchfiles (>=0.13)", "websockets (>=10.4)"]
@@ -1642,5 +1615,5 @@ files = [
 
 [metadata]
 lock-version = "2.0"
-python-versions = "3.10.14"
-content-hash = "4d0b2c75bdb1dabb7e7a0d8a12a4f7e94dade5665d8ccff621919379a14e30b4"
+python-versions = "3.12.8"
+content-hash = "ad27e1f48576814a8e5f6e77dff8abd7fd9b22beff9088befa40395bc9321d9e"
diff --git a/pyproject.toml b/pyproject.toml
index 98b72bd0..baed40b2 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,7 +16,7 @@ name = "Naoki Aoyama"
 # Sphinx 用 End
 
 [tool.poetry.dependencies]
-python = "3.10.14"
+python = "3.12.8"
 
 [tool.poetry.group.dev.dependencies]
 pip = "^24.0.0"