diff --git a/action.yml b/action.yml
index 0cea738b..30500186 100644
--- a/action.yml
+++ b/action.yml
@@ -43,12 +43,13 @@ inputs:
       The label is used to remove the runner from GitHub when the runner is not needed anymore.
       This input is required if you use the 'stop' mode.
     required: false
-  ec2-instance-id:
+  ec2-instance-ids:
     description: >-
-      EC2 Instance Id of the created runner.
-      The id is used to terminate the EC2 instance when the runner is not needed anymore.
+      EC2 Instance Id(s) of the created runner(s).
+      The Id(s) are used to terminate the EC2 instance(s) when the runner is not needed anymore.
       This input is required if you use the 'stop' mode.
     required: false
+    default: 'null'
   iam-role-name:
     description: >-
       IAM Role Name to attach to the created EC2 instance.
@@ -65,6 +66,11 @@ inputs:
     description: >-
       Directory that contains actions-runner software and scripts. E.g. /home/runner/actions-runner.
     required: false
+  runner-count:
+    description: >-
+      Number of instances to create.
+    required: false
+    default: '1'
 outputs:
   label:
     description: >-
@@ -72,9 +78,9 @@ outputs:
       The label is used in two cases:
       - to use as the input of 'runs-on' property for the following jobs;
       - to remove the runner from GitHub when it is not needed anymore.
-  ec2-instance-id:
+  ec2-instance-ids:
     description: >-
-      EC2 Instance Id of the created runner.
+      EC2 Instance Id(s) of the created runner(s).
       The id is used to terminate the EC2 instance when the runner is not needed anymore.
 runs:
   using: node12
diff --git a/src/aws.js b/src/aws.js
index 028dca42..7aca7758 100644
--- a/src/aws.js
+++ b/src/aws.js
@@ -20,8 +20,8 @@ function buildUserDataScript(githubRegistrationToken, label) {
       '#!/bin/bash',
       'mkdir actions-runner && cd actions-runner',
       'case $(uname -m) in aarch64) ARCH="arm64" ;; amd64|x86_64) ARCH="x64" ;; esac && export RUNNER_ARCH=${ARCH}',
-      'curl -O -L https://github.com/actions/runner/releases/download/v2.280.3/actions-runner-linux-${RUNNER_ARCH}-2.280.3.tar.gz',
-      'tar xzf ./actions-runner-linux-${RUNNER_ARCH}-2.280.3.tar.gz',
+      'curl -O -L https://github.com/actions/runner/releases/download/v2.284.0/actions-runner-linux-${RUNNER_ARCH}-2.284.0.tar.gz',
+      'tar xzf ./actions-runner-linux-${RUNNER_ARCH}-2.284.0.tar.gz',
       'export RUNNER_ALLOW_RUNASROOT=1',
       'export DOTNET_SYSTEM_GLOBALIZATION_INVARIANT=1',
       `./config.sh --url https://github.com/${config.githubContext.owner}/${config.githubContext.repo} --token ${githubRegistrationToken} --labels ${label}`,
@@ -38,8 +38,8 @@ async function startEc2Instance(label, githubRegistrationToken) {
   const params = {
     ImageId: config.input.ec2ImageId,
     InstanceType: config.input.ec2InstanceType,
-    MinCount: 1,
-    MaxCount: 1,
+    MinCount: config.input.runnerCount,
+    MaxCount: config.input.runnerCount,
     UserData: Buffer.from(userData.join('\n')).toString('base64'),
     SubnetId: config.input.subnetId,
     SecurityGroupIds: [config.input.securityGroupId],
@@ -49,9 +49,9 @@ async function startEc2Instance(label, githubRegistrationToken) {
 
   try {
     const result = await ec2.runInstances(params).promise();
-    const ec2InstanceId = result.Instances[0].InstanceId;
-    core.info(`AWS EC2 instance ${ec2InstanceId} is started`);
-    return ec2InstanceId;
+    const ec2InstanceIds = result.Instances.map(inst => inst.InstanceId);
+    core.info(`AWS EC2 instances ${ec2InstanceIds} are started`);
+    return ec2InstanceIds;
   } catch (error) {
     core.error('AWS EC2 instance starting error');
     throw error;
@@ -62,32 +62,32 @@ async function terminateEc2Instance() {
   const ec2 = new AWS.EC2();
 
   const params = {
-    InstanceIds: [config.input.ec2InstanceId],
+    InstanceIds: config.input.ec2InstanceIds,
   };
 
   try {
     await ec2.terminateInstances(params).promise();
-    core.info(`AWS EC2 instance ${config.input.ec2InstanceId} is terminated`);
+    core.info(`AWS EC2 instances ${config.input.ec2InstanceIds} are terminated`);
     return;
   } catch (error) {
-    core.error(`AWS EC2 instance ${config.input.ec2InstanceId} termination error`);
+    core.error(`AWS EC2 instances ${config.input.ec2InstanceIds} termination error`);
     throw error;
   }
 }
 
-async function waitForInstanceRunning(ec2InstanceId) {
+async function waitForInstanceRunning(ec2InstanceIds) {
   const ec2 = new AWS.EC2();
 
   const params = {
-    InstanceIds: [ec2InstanceId],
+    InstanceIds: ec2InstanceIds,
   };
 
   try {
     await ec2.waitFor('instanceRunning', params).promise();
-    core.info(`AWS EC2 instance ${ec2InstanceId} is up and running`);
+    core.info(`AWS EC2 instances ${ec2InstanceIds} are up and running`);
     return;
   } catch (error) {
-    core.error(`AWS EC2 instance ${ec2InstanceId} initialization error`);
+    core.error(`AWS EC2 instances ${ec2InstanceIds} initialization error`);
     throw error;
   }
 }
diff --git a/src/config.js b/src/config.js
index 13bf86a1..fb858e42 100644
--- a/src/config.js
+++ b/src/config.js
@@ -11,9 +11,10 @@ class Config {
       subnetId: core.getInput('subnet-id'),
       securityGroupId: core.getInput('security-group-id'),
       label: core.getInput('label'),
-      ec2InstanceId: core.getInput('ec2-instance-id'),
+      ec2InstanceIds: JSON.parse(core.getInput('ec2-instance-ids')),
       iamRoleName: core.getInput('iam-role-name'),
       runnerHomeDir: core.getInput('runner-home-dir'),
+      runnerCount: core.getInput('runner-count'),
     };
 
     const tags = JSON.parse(core.getInput('aws-resource-tags'));
@@ -47,7 +48,7 @@ class Config {
         throw new Error(`Not all the required inputs are provided for the 'start' mode`);
       }
     } else if (this.input.mode === 'stop') {
-      if (!this.input.label || !this.input.ec2InstanceId) {
+      if (!this.input.label || !this.input.ec2InstanceIds) {
         throw new Error(`Not all the required inputs are provided for the 'stop' mode`);
       }
     } else {
diff --git a/src/gh.js b/src/gh.js
index abf9af94..f444b5be 100644
--- a/src/gh.js
+++ b/src/gh.js
@@ -11,7 +11,7 @@ async function getRunner(label) {
   try {
     const runners = await octokit.paginate('GET /repos/{owner}/{repo}/actions/runners', config.githubContext);
     const foundRunners = _.filter(runners, { labels: [{ name: label }] });
-    return foundRunners.length > 0 ? foundRunners[0] : null;
+    return foundRunners.length > 0 ? foundRunners : null;
   } catch (error) {
     return null;
   }
@@ -32,29 +32,34 @@ async function getRegistrationToken() {
 }
 
 async function removeRunner() {
-  const runner = await getRunner(config.input.label);
+  const runners = await getRunner(config.input.label);
   const octokit = github.getOctokit(config.input.githubToken);
 
   // skip the runner removal process if the runner is not found
-  if (!runner) {
+  if (!runners) {
     core.info(`GitHub self-hosted runner with label ${config.input.label} is not found, so the removal is skipped`);
     return;
   }
 
-  try {
-    await octokit.request('DELETE /repos/{owner}/{repo}/actions/runners/{runner_id}', _.merge(config.githubContext, { runner_id: runner.id }));
-    core.info(`GitHub self-hosted runner ${runner.name} is removed`);
-    return;
-  } catch (error) {
-    core.error('GitHub self-hosted runner removal error');
-    throw error;
+  const errors = [];
+  for (const runner of runners) {
+    try {
+      await octokit.request('DELETE /repos/{owner}/{repo}/actions/runners/{runner_id}', _.merge(config.githubContext, { runner_id: runner.id }));
+      core.info(`GitHub self-hosted runner ${runner.name} is removed`);
+    } catch (error) {
+      core.error(`GitHub self-hosted runner ${runner} removal error: ${error}`);
+      errors.push(error);
+    }
+  }
+  if (errors.length > 0) {
+    core.setFailed('Failures occurred when removing runners.');
   }
 }
 
 async function waitForRunnerRegistered(label) {
-  const timeoutMinutes = 5;
-  const retryIntervalSeconds = 10;
-  const quietPeriodSeconds = 30;
+  const timeoutMinutes = 8;
+  const retryIntervalSeconds = 20;
+  const quietPeriodSeconds = 40;
   let waitSeconds = 0;
 
   core.info(`Waiting ${quietPeriodSeconds}s for the AWS EC2 instance to be registered in GitHub as a new self-hosted runner`);
@@ -63,7 +68,7 @@ async function waitForRunnerRegistered(label) {
 
   return new Promise((resolve, reject) => {
     const interval = setInterval(async () => {
-      const runner = await getRunner(label);
+      const runners = await getRunner(label);
 
       if (waitSeconds > timeoutMinutes * 60) {
         core.error('GitHub self-hosted runner registration error');
@@ -71,14 +76,15 @@ async function waitForRunnerRegistered(label) {
         reject(`A timeout of ${timeoutMinutes} minutes is exceeded. Your AWS EC2 instance was not able to register itself in GitHub as a new self-hosted runner.`);
       }
 
-      if (runner && runner.status === 'online') {
-        core.info(`GitHub self-hosted runner ${runner.name} is registered and ready to use`);
+      if (runners && runners.every((runner => runner.status === 'online'))) {
+        core.info(`GitHub self-hosted runners ${runners} are registered and ready to use`);
         clearInterval(interval);
         resolve();
       } else {
         waitSeconds += retryIntervalSeconds;
         core.info('Checking...');
       }
+
     }, retryIntervalSeconds * 1000);
   });
 }
diff --git a/src/index.js b/src/index.js
index 00bc5152..bb373ad9 100644
--- a/src/index.js
+++ b/src/index.js
@@ -3,17 +3,17 @@ const gh = require('./gh');
 const config = require('./config');
 const core = require('@actions/core');
 
-function setOutput(label, ec2InstanceId) {
+function setOutput(label, ec2InstanceIds) {
   core.setOutput('label', label);
-  core.setOutput('ec2-instance-id', ec2InstanceId);
+  core.setOutput('ec2-instance-ids', ec2InstanceIds);
 }
 
 async function start() {
   const label = config.generateUniqueLabel();
   const githubRegistrationToken = await gh.getRegistrationToken();
-  const ec2InstanceId = await aws.startEc2Instance(label, githubRegistrationToken);
-  setOutput(label, ec2InstanceId);
-  await aws.waitForInstanceRunning(ec2InstanceId);
+  const ec2InstanceIds = await aws.startEc2Instance(label, githubRegistrationToken);
+  setOutput(label, ec2InstanceIds);
+  await aws.waitForInstanceRunning(ec2InstanceIds);
   await gh.waitForRunnerRegistered(label);
 }