To resume data writing onto a disk, a recording start position detection means (19) detects a recording start position, and a synchronous setting means (20) synchronizes recording data with recorded data on a disk so that recording data successive to the recorded data on the disk can be additionally written onto the disk without a break. Data writing onto a disk is suspended until an amount of data equivalent to data writing capacity has been stored in the buffer memory (13). Data writing is resumed upon detection of the fact that an amount of data equivalent to data writing capacity has been stored in the buffer memory (13). With the above, power consumption can be reduced during a period when recording capability of a disk recording device exceeds the data transfer speed.