PURPOSE: To obtain a two beam optical head in which simultaneous focusing of two light spots can be achieved and performance of simultaneous erasing, recording and reproducing is easily secured, even if an inexpensive optical system using a lens having chromatic aberration is used.

CONSTITUTION: This optical head comprises a monolithic semiconductor laser array 1 having two emitting points 1a, 1b which radiates two light beams of the first and the second having different light intensity respectively, and a forming means which forms light spots 9a, 9b of the first and the second on a magneto-optical disk 6 by passing two light beams through the almost same light path. And the direction of arranging the first emitting point la and the second emitting point 1b is tilted by angle 8 to a plane being perpendicular to an optical axis of the optical system.