To provide write protection of a disc in a bare state that is usually used in a cartridge having a recognition switch for write protection, such as a DVD-RAM, write protection information is recorded in a Lead-in area, a Lead-out area or a recording information area other than a user data area of the disc, and the data is protected from unwanted overwriting or erasing using the write protection information. Even when the write protection information stored on a disc does not match the state of a recognition switch of a case for write protection, the data can be prevented from unwanted overwriting or erasing. Thus, write protection can be ensured when a recordable and/or rewritable recording medium, such as a DVD-RAM, a DVD-R or a DVD-RW, is used in a bare state.