A method, medium, and apparatus for deleting and/or restoring time-series contents stored in a recording medium. When the time-series contents are stored in the recording medium, deleting of data that is present in a first area of a recording medium includes periodically inserting a time stamp into the contents, generating deletion data positional information based on the time stamp, the deletion data positional information representing a relative position of the deletion data within the contents, storing the deletion data positional information and the deletion data in a second area of the recording medium, and designating the first area as overwritable on the recording medium. Even if the recording medium is reloaded in another disk drive and under another operating system, data deleted from the recording medium can be easily restored.