A method for adjusting a height position of a polishing head, comprising moving the polishing head to a height position at which the polishing head comes in noncontact with the polishing pad with the polishing head holding no workpiece, and then rotating at least one of the polishing head and the turn table; measuring the load torque current of the at least one of the polishing head and the turn table rotated with the torque-measuring mechanism while the height-adjusting mechanism moves the polishing head toward the polishing pad until the polishing head contacts the polishing pad, and recording the height position of the polishing head as a reference position when a variation in the measured load torque current exceeds a threshold; and adjusting the height position of the polishing head to the predetermined position on the basis of a distance from the reference position.