diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 355851c..e3c1c21 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -14,7 +14,7 @@ jobs:
       fail-fast: false
       matrix:
         toolchain:
-          - 1.42.0-x86_64-unknown-linux-gnu
+          - 1.70.0-x86_64-unknown-linux-gnu
           - stable-x86_64-unknown-linux-gnu
 
     name: Rustfmt (${{ matrix.toolchain }})
@@ -43,16 +43,16 @@ jobs:
       fail-fast: false
       matrix:
         toolchain:
-          - 1.42.0-x86_64-pc-windows-msvc
-          - 1.42.0-x86_64-apple-darwin
-          - 1.42.0-x86_64-unknown-linux-gnu
+          - 1.70.0-x86_64-pc-windows-msvc
+          - 1.70.0-x86_64-apple-darwin
+          - 1.70.0-x86_64-unknown-linux-gnu
           - stable-x86_64-pc-windows-msvc
           - stable-x86_64-apple-darwin
           - stable-x86_64-unknown-linux-gnu
         include:
-          - { toolchain: 1.42.0-x86_64-pc-windows-msvc  , os: windows-2019 }
-          - { toolchain: 1.42.0-x86_64-apple-darwin     , os: macos-11     }
-          - { toolchain: 1.42.0-x86_64-unknown-linux-gnu, os: ubuntu-20.04 }
+          - { toolchain: 1.70.0-x86_64-pc-windows-msvc  , os: windows-2019 }
+          - { toolchain: 1.70.0-x86_64-apple-darwin     , os: macos-11     }
+          - { toolchain: 1.70.0-x86_64-unknown-linux-gnu, os: ubuntu-20.04 }
           - { toolchain: stable-x86_64-pc-windows-msvc  , os: windows-2019 }
           - { toolchain: stable-x86_64-apple-darwin     , os: macos-11     }
           - { toolchain: stable-x86_64-unknown-linux-gnu, os: ubuntu-20.04 }
@@ -97,7 +97,7 @@ jobs:
       fail-fast: false
       matrix:
         toolchain:
-          - 1.42.0-x86_64-unknown-linux-gnu
+          - 1.70.0-x86_64-unknown-linux-gnu
           - stable-x86_64-unknown-linux-gnu
         python-version:
           - '3.6' # https://packages.ubuntu.com/bionic/python3
@@ -136,14 +136,14 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v3
 
-      - name: Setup `1.60.0-x86_64-unknown-linux-gnu`
+      - name: Setup `1.70.0-x86_64-unknown-linux-gnu`
         uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: 1.60.0-x86_64-unknown-linux-gnu
+          toolchain: 1.70.0-x86_64-unknown-linux-gnu
 
-      - name: 'Override `1.60.0-x86_64-unknown-linux-gnu'
+      - name: 'Override `1.70.0-x86_64-unknown-linux-gnu'
         run: |
-          rustup override set 1.60.0-x86_64-unknown-linux-gnu
+          rustup override set 1.70.0-x86_64-unknown-linux-gnu
 
       - name: Setup Python 3.9
         uses: actions/setup-python@v4
diff --git a/Cargo.toml b/Cargo.toml
index c630983..d7ad692 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -2,7 +2,7 @@
 name = "ac-library-rs"
 version = "0.2.0-alpha.1"
 edition = "2018"
-rust-version = "1.42"
+rust-version = "1.70"
 description = "A Rust port of AtCoder Library (ACL)."
 license = "CC0-1.0"
 repository = "https://github.com/rust-lang-ja/ac-library-rs"
diff --git a/README.md b/README.md
index f27423d..7b956e6 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # ac-library-rs
 
 [![CI](https://github.com/rust-lang-ja/ac-library-rs/workflows/CI/badge.svg)](https://github.com/rust-lang-ja/ac-library-rs/actions?workflow=CI)
-[![Rust 2018 1.42.0+](https://img.shields.io/badge/rust%202018-1.42.0+-lightgray.svg)](https://www.rust-lang.org)
+[![Rust 2018 1.70.0+](https://img.shields.io/badge/rust%202018-1.70.0+-lightgray.svg)](https://www.rust-lang.org)
 [![Crates.io](https://img.shields.io/crates/v/ac-library-rs.svg)](https://crates.io/crates/ac-library-rs)
 [![License](https://img.shields.io/crates/l/ac-library-rs.svg)](https://crates.io/crates/ac-library-rs)
 
diff --git a/rust-toolchain b/rust-toolchain
index a50908c..832e9af 100644
--- a/rust-toolchain
+++ b/rust-toolchain
@@ -1 +1 @@
-1.42.0
+1.70.0