To provide a means that detects the erroneous recognition of a standard excitation starting angle of a PM (Permanent Magnet)-type motor.

In the PM-type motor provided with a magnetic pole detector that detects the polarity of a permanent magnet and a position detector that detects an electrical angle of a movable body, electrical angle intervals between changing points of a magnetic pole detection signal outputted by the magnetic pole detector are measured and compared by the position detector, and when a difference between the electrical angle interval between the changing points and a set electrical angle interval exceeds an allowable angle interval, excitation to a coil of each phase is stopped.