A disk recording medium playback apparatus wherein a plurality of disks are stored in a magazine, fetched one at a time for reproduction, and the information read from each fetched disk is written to a buffer memory at a higher speed than the speed at which the data is read out from the buffer memory and reproduced, thereby allowing a controlling apparatus enough time to sense by address codes in the reproduced data that reproduction of one disk is finished and that the first disk must be replaced in the magazine and another disk fetched. During replacement of a disk and retrieval of a new disk, data is read out from the buffer memory and reproduced so that there is no interruption of the reproduced data.