A disk changer apparatus includes a rotation base on which a turntable and a head are mounted. The rotation base can rotate about the rear end thereof as a fulcrum. The disk changer apparatus further includes a base supporter opposed to the top end of the rotation base when the rotation base moves to a driving position where the rotation base can drive a disk selected from a plurality of disks, a lock member movably mounted on the rotation base, and a lock control mechanism for causing the lock member to be connected to the base supporter when the rotation base moves to the driving position. The disk changer apparatus having such a structure stably supports both ends of the rotation base when the rotation base rotates to the driving position.