An information management method for managing whether to allow playback of copyrighted content includes an invalidating step, executed by playback management means when an invalidating request for content recorded on a recording medium is received, of registering the content in playback-management information as being in a playback-prohibition state; a playback processing step, executed by playback controlling means when a playback request for content on the recording medium is received, of permitting playback only when the content is not in the playback-prohibition state with reference to the playback-management information; and an invalidation canceling step, executed by the playback controlling means when playback-permission information associated with content in the playback-prohibition state is obtained, of updating the playback-management information so that the playback-prohibition state of the content is canceled.