PURPOSE: To support a disk on a turntable with an appropriate attractive force in spite of the change of the height of a hub by providing a magnet which attracts the hub in the center part of the disk, a frictional material to support the magnet with the frictional force of the hub by abutting on the hub, and a spring leaded between the magnet and the frictional material.

CONSTITUTION: The frictional material 16 such as rubber, etc., to prevent slippage when rotating by abutting on the hub 12 of the disk 11 loaded on the turntable 14, and the magnet 17 to pressurize contact with the frictional material 16 by attracting the hub 12 are provided at a center shaft 15. Furthermore, the spring 18 of coil shape is provided between the frictional material 16 and the magnet 17, and the spring constant of the spring 18 can be set so that it can be varied corresponding to a ratio of change of the attractive force of the magnet 17 in accordance with a ratio of change of the attractive force of the magnet 17 changing in proportion to distance between a magnetic plate 13 and the magnet 17. Therefore, when various kinds of height of the hub 12 exist, it is possible to easily respond to every kind of disk by varying the frictional material 16 with the spring 18 corresponding to each kind of height. In such a way, the disk can be surely supported by absorbing the difference of the height of the hub.