Abstract: An optical disc clamp mechanism that is capable of selectively playing back either of a compact disc or a mini disc. The clamp mechanism includes a circular disc receiving section for contacting a reference surface of either of the compact disc or the mini disc and further includes a magnetic clamp unit for clamping the mini disc by magnetic attraction with a magnetically attractable member of the mini disc. A first conical or spherical taper cone portion for engaging the center hole of the mini disc is mounted to the disc receiving section and a second conical or spherical taper cone portion for engaging the center hole of the compact disc is mounted to the disc receiving section. The first taper cone portion is located inwardly of the second taper cone portion and protrudes from the second taper cone portion in the axial direction. The magnetic clamp unit further includes a stopper element for preventing detachment of the first and second taper cone portions from the disc receiving section.