25a and 25b and the frictional force between the disk and the inner surfaces of the disk cassette as can be understood from this graph the load torque applied to the disk decreases as the rotation speed of the disk increases when for example the rotation speed of the disk is about 300 rpm all the disks a b and c satisfy the critical load torque c l t 10 g cm which prevents the undesirable slippage of the disk on the turntable 10 while when the rotation speed of the disk is about 600 rpm the disks b and c fail to satisfy the critical value of 10 g cm thus it is believed that if the drive pin 12 of the turntable 10 collides with the forward edge 5a of the engaging hole 5 of the disk 1 at a speed lower than 300 rpm the undesirable slippage of the disk 1 will not occur an additional aspect of the present invention is designed to put the above mentioned consideration into practice as will become clear as the description proceeds in accordance with the present invention the disk drive is controlled in such a manner that as the turntable starts to rotate its speed is held to a lower level to prevent slippage of the disk on the turntable.