Where can I find in-detail info of the 'charges by service'?

To find detailed information about your "charges by service," you have several options:

1. AWS Cost Explorer: This tool allows you to analyze your costs by different dimensions including services, regions, and usage types. You can access it from the AWS Management Console by searching for "Cost Explorer."

2. AWS Billing Dashboard: Once signed in, you can visit the Billing dashboard and look for the "Charges by service" section. This provides a breakdown of what services are generating costs.

3. AWS Cost and Usage Report (CUR): For more detailed reports, you can use AWS Data Exports to create exports of the AWS Cost and Usage Report. This publishes your billing reports to an Amazon S3 bucket that you own, providing granular usage information.

For your specific EBS charges, you can use Cost Explorer to filter by the EBS service and group by usage type to see exactly what's generating those costs.

To delete EBS volumes that you no longer need:

1. Go to the EC2 console
2. Navigate to the "Volumes" section in the left sidebar
3. Select the unused EBS volumes
4. Click "Actions" and then "Delete volume"

Note that you can only delete EBS volumes that are not attached to any instances. If a volume is attached, you'll need to detach it first before deletion.
Sources
Billing question | AWS re:Post
AWS Billing reports for Amazon EFS - Amazon Elastic File System

Hello.

When I check the contents of the image, it appears that EBS snapshot charges are incurred in the Seoul region (ap-northeast-2).
Open the ap-northeast-2 region from the management console and try deleting the EBS snapshot by following the steps in the document below.
https://docs.aws.amazon.com/ebs/latest/userguide/ebs-deleting-snapshot.html#ebs-delete-snapshot