To miniaturize an optical disk device by efficiently rotating a DC servo motor for reducing consumption power and improving heat radiation of the optical disk device or the like.

This motor drive circuit defines the supply timing of a drive current to drive coils 113 (a, b, and c) supplied from a power supply 120 based on an output signal form Hall elements 114 (a, b, and c) incorporated in a servo motor, detects the magnetic polarity of a rotor magnet 112 with the Hall elements, eliminates the influence due to magnetic force from the drive coils included in an output signal being outputted from the Hall elements and the component of the deviation of output caused by the mounted position of the Hall elements when the magnetic polarity of the rotor magnet is detected with the Hall element, and supplies a drive current from the power supply to each drive coil.