It is an object of the present invention to improve reliability of defect management. This is obtained by providing a plurality of management data areas each including a defect management area typically in a lead-in zone of a disc inner-side region enclosed by a circumference having a predetermined radius on a disc-shaped recording medium. In addition, the plurality of the defect management areas are placed at locations, which are separated from each other in the radial direction of the disc-shaped recording medium, sandwiching a recording/reproduction condition adjustment area OPC having a relatively large size. If information stored in one defect management area is found to be different to information stored in another defect management area, then the information in the defect management areas is made uniform by copying the information stored in an earlier defect management area to a later defect management area in a predetermined priority order.