To provide a motor drive and a motor driving method, with which stable rotation control can be conducted, even if an abnormality occurs in the external control signal.

The motor drive 2 PWM-controls a motor M based on the external control signal PWM1 which is pulse width-modulated. The drive is provided with an internal control signal generating part 4 the generates an internal control signal PWM2 which is pulse width-modulated; an external control signal monitoring part 5 that monitors whether rise or fall or pulse edges of them appear in a prescribed period, in the external control signal PWM1 and outputting a monitoring result; and a control signal selecting part 6 that controls the rotation of the motor M, based on the external control signal PWM1, when the pulse edge appears and controlling the rotation of the motor M, based on the internal control signal PWM2, when the pulse edge does not appear in the monitoring result in the external control signal monitoring part 5.