To provide a disk chucking device capable of detecting a chucking-mistake before rotating a disk by judging whether a single disk is correctly chucked to a turntable or not with a simple constitution.

In this disk chucking device, a lead wire (a) to a chucking-mistake detecting circuit is extended from a stabilizer 1 and a lead wire (b) is similarly extended from a turntable 2. In the case of a chucking success, a disk 3 is held between the stabilizer 1 and the turntable 2 in a state in which the center protrusion 2a of the turntable 2 is fitted to the center hole 3a of the disk 3 and the stabilizer 1 and the turntable are brought into contact mutually and conduction is caused. In the case of a chucking failure, the disk 3 is held incorrectly between the stabilizer 1 and the turntable 2 and the stabilizer 1 and the turntable 2 are brought into non-contact and conduction is not caused.