You can configure a lock on a resource group to prevent the accidental deletion.

As an administrator, you may need to lock a subscription, resource group, or resource to prevent other users in your organization from accidentally deleting or modifying critical resources. You can set the lock level to  CanNotDelete  or  ReadOnly . In the portal, the locks are called  Delete  and  Read-only  respectively.

CanNotDelete  means authorized users can still read and modify a resource, but they can ' t delete the resource.

ReadOnly  means authorized users can read a resource, but they can ' t delete or update the resource. Applying this lock is similar to restricting all authorized users to the permissions granted by the  Reader  role.