A recording medium that is a write-once recording medium with data rewritability, thereby increasing the usability of the write-once recording medium, is provided. In a write-once recording medium, a main data area has a normal record and playback sub-area (a user data section), a rewriting replacement sub-area (an OSA), and a replacement management sub-area (an ISA). In response to a request to write data to an address at which data has been recorded, the rewritten data is recorded in the rewriting replacement sub-area (the OSA), and replacement management information that associates the original address with the address in the rewriting replacement sub-area is recorded into the replacement management sub-area (the ISA). Thus, data rewriting is achieved. Accordingly, a write-once recording medium can be substantially used as a data rewritable recording medium.