diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0c9ad291..1adf19ff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,17 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
   If rustup is not yet installed, this action downloads [rustup-init for the current platform](https://rust-lang.github.io/rustup/installation/other.html#manual-installation) using HTTPS with tlsv1.2+, verifies SHA256 checksum, and then installs rustup using it.
 
+  This also supports installing additional components at the same time by `+<additional>` syntax:
+
+  ```yaml
+  - uses: taiki-e/install-action@v2
+    with:
+      # Install rust stable with rustfmt component and wasm32-wasip1 target.
+      tool: rust+rustfmt+wasm32-wasip1
+      # When installing another rust version:
+      # tool: rust@nightly + rustfmt + wasm32-wasip1
+  ```
+
 ## [2.76.0] - 2026-05-04
 
 - Support `mdbook-d2`. ([#1737](https://github.com/taiki-e/install-action/pull/1737), thanks @nhu)
diff --git a/README.md b/README.md
index 41d81e12..c1c97fdb 100644
--- a/README.md
+++ b/README.md
@@ -58,6 +58,17 @@ You can also omit patch version.
     tool: cargo-hack@0.5
 ```
 
+For some tools, we support installing additional components at the same time by `+<additional>` syntax:
+
+```yaml
+- uses: taiki-e/install-action@v2
+  with:
+    # Install rust stable with rustfmt component and wasm32-wasip1 target.
+    tool: rust+rustfmt+wasm32-wasip1
+    # When installing another rust version:
+    # tool: rust@nightly + rustfmt + wasm32-wasip1
+```
+
 To install multiple tools:
 
 ```yaml
@@ -73,6 +84,16 @@ Or:
 - uses: taiki-e/install-action@cargo-minimal-versions
 ```
 
+Tool names can also be separated with whitespaces (line, space, tab).
+
+```yaml
+- uses: taiki-e/install-action@v2
+  with:
+    tool: |
+      cargo-hack
+      cargo-minimal-versions
+```
+
 ## Supported tools
 
 See [TOOLS.md](TOOLS.md) for the list of tools that are installed from manifests managed in this action.
diff --git a/main.sh b/main.sh
index d36573fa..0782604c 100755
--- a/main.sh
+++ b/main.sh
@@ -43,11 +43,11 @@ normalize_comma_or_space_separated() {
   if [[ "${list}" == *","* ]]; then
     # If a comma is contained, consider it is a comma-separated list.
     # Drop leading and trailing whitespaces in each element.
-    sed -E 's/ *, */,/g; s/^.//; s/,,$/,/' <<<",${list},"
+    sed -E 's/ *\+ */+/g; s/ *, */,/g; s/^.//; s/,,$/,/' <<<",${list},"
   else
     # Otherwise, consider it is a whitespace-separated list.
     # Convert whitespace characters into comma.
-    sed -E 's/ +/,/g; s/^.//' <<<" ${list} "
+    sed -E 's/ *\+ */+/g; s/ +/,/g; s/^.//' <<<" ${list} "
   fi
 }
 _sudo() {
@@ -735,7 +735,12 @@ esac
 
 unsupported_tools=()
 for tool in "${tools[@]}"; do
-  if [[ "${tool}" == *"@"* ]]; then
+  additional=''
+  if [[ "${tool}" == *'+'* ]]; then
+    additional="${tool#*+}"
+    tool="${tool%%+*}"
+  fi
+  if [[ "${tool}" == *'@'* ]]; then
     version="${tool#*@}"
     tool="${tool%@*}"
     if [[ "${tool}" != 'rust' ]]; then
@@ -749,6 +754,12 @@ for tool in "${tools[@]}"; do
   else
     version=latest
   fi
+  if [[ -n "${additional}" ]]; then
+    case "${tool}" in
+      rust) ;;
+      *) bail "<tool_name>+<additional> syntax is not supported for ${tool}" ;;
+    esac
+  fi
   installed_bin=()
   case "${tool}" in
     rust)
@@ -758,6 +769,28 @@ for tool in "${tools[@]}"; do
       info "installing ${tool}@${version}"
       export RUSTUP_MAX_RETRIES="${RUSTUP_MAX_RETRIES:-10}"
       rustup_args=(--profile minimal)
+      if [[ -n "${additional}" ]]; then
+        component=''
+        target=''
+        while read -rd+; do
+          case "${REPLY}" in
+            # Last checked: nightly-2026-05-03
+            # rustup component list
+            # rustup target list
+            cargo | cargo-* | clippy | clippy-* | llvm-* | miri | miri-* | rust-* | rustc-* | rustfmt | rustfmt-*) component+=",${REPLY}" ;;
+            *) target+=",${REPLY}" ;;
+          esac
+        done <<<"${additional}+"
+        if [[ -n "${component}" ]]; then
+          if [[ "${component}," == *',miri,'* ]] && [[ "${component}," != *',rust-src,'* ]]; then
+            component+=',rust-src'
+          fi
+          rustup_args+=(--component "${component#,}")
+        fi
+        if [[ -n "${target}" ]]; then
+          rustup_args+=(--target "${target#,}")
+        fi
+      fi
       if type -P rustup >/dev/null; then
         # --no-self-update is necessary because the windows environment cannot self-update rustup.exe.
         g retry rustup toolchain add "${version}" --no-self-update "${rustup_args[@]}"
diff --git a/tools/ci/tool-list.sh b/tools/ci/tool-list.sh
index 95797d6a..4f3d437e 100755
--- a/tools/ci/tool-list.sh
+++ b/tools/ci/tool-list.sh
@@ -199,13 +199,35 @@ case "${runner}" in
   # requires glibc 2.17 / musl 1.2
   centos:6 | alpine:3.2) ;;
   *)
-    case $((RANDOM % 5)) in
-      0) tools+=(rust) ;;
-      1) tools+=(rust@stable) ;;
-      2) tools+=(rust@nightly) ;;
-      3) tools+=(rust@1.93) ;;
-      4) tools+=(rust@1.93.0) ;;
+    case $((RANDOM % 4)) in
+      0) rust=rust ;;
+      1) rust=rust@stable ;;
+      2) rust=rust@nightly ;;
+      3) rust=rust@1.93 ;;
     esac
+    case $((RANDOM % 3)) in
+      0) ;;
+      1) rust+='+thumbv6m-none-eabi' ;;
+      2) rust+=' + thumbv6m-none-eabi' ;;
+    esac
+    if [[ "${rust}" == *'nightly'* ]]; then
+      component=miri
+    else
+      component=rustfmt
+    fi
+    case $((RANDOM % 5)) in
+      0) ;;
+      1) rust+="+${component}" ;;
+      2) rust+=" + ${component}" ;;
+      3) rust+=" +${component}" ;;
+      4) rust+="+ ${component}" ;;
+    esac
+    case $((RANDOM % 3)) in
+      0) ;;
+      1) rust+='+thumbv7m-none-eabi' ;;
+      2) rust+=' + thumbv7m-none-eabi' ;;
+    esac
+    tools+=("${rust}")
     ;;
 esac
 case "${host_os}" in