It is an object of the present invention to improve reliability of defect management. 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, reliability of the defect management can be obtained. In addition, by placing a plurality of the defect management areas (information areas Info1 and Info2) 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, the reliability of the defect management areas can be further improved. Furthermore, by providing each of the defect management areas with a plurality of recording areas, which include a currently used recording area for recording defect management information and spare recording areas each
usable as a substitute for the currently used recording area, the currently used recording area can be replaced with one of the spare recording areas in accordance with an update count of the currently used recording area or error status of this currently used recording area.