A plurality of defect management areas (14A, 14B, 14C) are arranged on a write once type recording medium (10). Spare areas (12, 13) are divided into a plurality of partial spare areas (12A to 13B) and the defect list (21) is divided into partial defect lists (21A to 21D) so as to correspond to this. When recording data is recorded in a partial spare area, only the partial defect list corresponding to the partial spare area is recorded in the defect management area. In one defect management area, all the defect lists constituting the latest defect list are recorded.