When you no longer want to use an On-Demand Dedicated Host it can bereleased.Show details from next link. https://docs.aws.amazon.com/ja_jp/cli/latest/reference/ec2/release-hosts.html
aws ec2 release-hosts --host-ids host_id |
| Working with Dedicated Hosts - Amazon Elastic Compute Cloud : http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/how-dedicated-hosts-work.html |