PURPOSE: To reduce the size of a magnetic circuit driving a rocking arm, by increasing the arm rigidity through making the arm hollow shape and containing an optical system in the inside of arm to reduce the moment of inertia and to obtain an excellent reproducing frequency characteristic.

CONSTITUTION: The hollow rocking arm 20 has incorporatedly a pickup main body section 21. A semiconductor laser 22 is arranged din a lengthwise cavity of the arm 20 and on a line tying an optical axis of the optical system and a shaft 23. In the focus control, a current flows to a coil 11 fitted to the pickup main body 21, a magnetic force is produced with a magnet 9 fitted to an objective lens holding frame, and the holding frame is shifted in the optical axis of the optical system contained in the pickup main body 21 by the magnetic force. In the tracking and slide control, a magnetic force is produced between a coil 26 and a magnet 26 by flowing a current to the coil fitted to the rocking arm 20, and the arm 20 is turned by this magnetic force.