PURPOSE: To perform a high-quality overwriting operation by a method wherein an optical head and a magnetic head are driven collectively and the correction amount to a tracking direction of a light irradiation position by the optical head is detected.

CONSTITUTION: On the basis of a tracking error signal form an optical head 15, an electric current is made to flow to a magnetic-head tracking coil 63 by using a controller 29. Then, the coil 63 is subjected to a force in a tracking direction Tr according to the direction of the electric current; a magnetic-head driving shaft 61 is slid; a magnetic head is moved to the direction Tr by an amount corresponding to the movement of an image formation position by a light spot. The irradiation position by the light spot by means of the optical head 15 and the position of a magnetic-head supply range by means of a magnetic head 45 are not dislocated. When an electric current is made to flow to a clearance coil 65 on the basis of a focusing error signal from the optical head 15, the magnetic head 45 is moved, the clearance amount between the magnetic head 45 and a magneto-optical disk is kept definite and a recording quality can be improved.