PURPOSE: To easily record and reproduce first and second information signals by forming an optical disk by a laminated structure of an optical information recording surface and magnetic film and recording and reproducing the first and second information signals by using such optical disk.

CONSTITUTION: The optical disk 11 is formed with the magnetic film 12 suitable for a hard disk, etc., in place of an ordinary protective film. Namely, the optical disk 11 is constituted by forming a perpendicularly magnetized film by vapor deposition, etc., on a polycarbonate substrate 13, then forming a separating layer 15 by SiO2 thereon and in succession, forming the magnetic film 12 by sputtering, etc. As a result, the optical disk 11 is so formed that the disk is irradiated with a laser beam L by an optical pickup 4 and modulating magnetic fields are applied thereon by a modulating coil 5, by which the thermomagnetic recording of desired data on the perpendicularly magnetized film 14 is made possible in the same manner as with ordinary magneto-optical disk devices. The magnetic recording of the desired data on the magnetic film 12 by using a magnetic head 16 applied to a hard disk device, etc., is possible as well.