To improve the convenience of a record medium and allow a record process and reproduction process to be more easily performed than before. When a clip edit list update process 121 that updates video data and audio data recorded on a disc 32 is executed, an index file management section 72 manages and updates an index file held in an index file hold section 51 as the video data and audio data are updated. At this point, a search section 92 searches disc internal IDs assigned to clips or edit lists contained in the index file for the maximum value. A disc internal ID generation section 91 generates a disc internal ID according to the maximum value. An index file management section 72 updates the index file with the disc internal ID generated by the disc internal ID generation section 91.