The designated double speed number n is corrected by a ratio of a reproducing time of a VOBU calculated from the difference between VOBU_E_PTM and VOBU_S_PTM included in management information NV_PCK (navigation back) of the VOBU and a standard reproducing time (0.5 second) (S104), and an address of VOBU_SRI included in the VOBU of the recorded data is referred to by representing the corrected designation double speed number i as an exponent to obtain a VOBU to be subsequently reproduced (S109) The VOBU_SRI is referred to by representing the corrected designated double speed number i as the exponent, and an address of the VOBU to be subsequently reproduced can be obtained. Therefore, accurate reproducing speed can be achieved.