PURPOSE: To optimize the control by providing a first processing means controlling the gain/offset of a servo signal and a second processing means controlling the gain/offset of a first or a second data signal.

CONSTITUTION: When an optical disk is rotated and driven by a CAV system and recording data is reproduced, a reference signal being the regenerative signal of a reference clock among the regenerative signals obtained the reproduction is supplied to a first A/D converter 3 through a first analog signal processing part 1, and a master clock Pm is generated by a master clock generation circuit 8 based on a clock pit regenerative signal being the regenerative signal of a clock pit. The master clock Pm is supplied to a delay part 7.