Abstract: In an optical disk reproducing device capable of rotating an optical disk at a selected one of a plurality of preset linear velocities, vibration or shock of the device is detected during rotation of the disk, and the linear velocity of the disk is determined based on the result of the detection of the vibration or shock to restrain the vibration and shock within a permissible range. A limit rotational velocity above which the vibration or shock is excessive may be determined during a test conducted each time a disk is inserted, and the linear velocity of the disk during reproduction may be determined such that the rotational velocity does not exceed the limit rotational velocity.