A car-mounted disc player with an elastically supported drive unit including a turntable and a pickup; a clamper-supporting member rotatably supporting a clamper; a clamp mechanism for activating the clamper-supporting member to move toward or away from the drive unit so as to clamp or unclamp a disc between the turntable and the clamper; a lock mechanism for bringing the drive unit in a locked state or an unlocked state with respect to the chassis; and a change-over mechanism for activating the clamp and lock mechanisms. During change-over operations of the change-over mechanism for activating the clamp and lock mechanisms, the change-over mechanism can be halted at a half-locked position where the drive unit is brought in the locked state while the disc is kept in a clamped state by the turntable and the clamper.