PURPOSE: To allow high-speed tracking access by measuring the current necessary for removing the offset of a tracking error signal and passing the current steadily to a tracking coil, thereby removing the offset.

CONSTITUTION: An offset measuring means 28 which changes the driving current of the tracking coil 20 in an offset measuring mode and stores and holds the coil current value when the detection output of a neutral position by a position detecting means 26 is obtd. and an offset removing means 30 which removes the offset contained in the tracking error signal by steadily passing the offset measuring means 28 to the tracking coil 20. The offset is removed by steadily passing the current value for removing the offset to the tracking coil 20 and adjusting the balancing position by a spring member 24 so as to coincide with the neutral position of the position detector. The responsiveness is improved in this way and the high-speed tracking access is enabled.