PURPOSE: To always make incident light without inclination even when a pickup is inclined at the time of tilt servo by providing an optical path, which optical axis is made orthogonal to the radial direction of a disk, in one part of an optical path in an optics at least, and supporting the pickup turnably with the optical axis of this orthogonal optical path as a turning center axis.

CONSTITUTION: The optics is equipped with the optical path, which optical axis is made orthogonal to the radial direction of the disk, in one part at least and a supporting mechanism 9 supports a pickup 6 with the optical axis of the orthogonal optical path as the turning center axis. In such a way, when the title servo is executed by supporting the pickup 6 with the optical axis of the optical path, for which the optical axis is made orthogonal to the radial direction of the disk, as the turning center axis, the inclination of an optical axis O is same when inclining the pickup 6 and accordingly, the light without inclination is made incident to an objective lens 16 even at the time of the tilt servo. Thus, even when the pickup 6 is inclined, the light without inclination is made incident to the objective lens 16.