The same contents having different recording rates are recorded on a multi-layer disk. A plurality of contents or the same contents having different recording rates are independently recorded respectively in different layers of an optical disk having a plurality of recording layers. In order to record a plurality of contents or the same contents having different recording rates in parallel at that time, recording on the multi-layer optical disk is conducted by repeating an operation of dividing each content into recording units, recording a recording unit of one kind of information in a recording layer, and recording a recording unit of the other kind of information in a different recording layer.