A disk recording device records blocks of data such as musical information on a recordable disk where absolute addresses have been previously recorded. Address data indicating the starting and ending address of each block is recorded in a lead-in section, and recordable areas of the program area, such as unrecorded parts or unnecessarily recorded parts, are detected on the basis of the address data of each block. The respective lengths of the recordable areas are indicated. Hence the user can easily identify unrecorded or unnecessarily recorded areas that are long enough for further recording.