A DC voltage value is obtained at least at an inside position, an intermediate position, and an outside position on a disc (1) from a drive signal that is supplied to a focusing coil (4) built into an optical pickup (2). From the DC voltage values is obtained a relationship of a position between the respective positions and the DC voltage value, and this relationship is stored into a memory circuit (12). Then, during recording or playback, the DC voltage value that is calculated on the basis of the recording or playback position of the signal at that time and the AC signal included in the drive signal that is supplied to the focusing coil (4) are added to create a signal to be supplied to a tilt adjustment coil (6).