A motor control device is disclosed that reduces the shock caused by torque increase during switching output of a motor's power generator from PWM wave voltage driving to square-wave voltage driving. Switching of PWM wave voltage driving and square-wave voltage driving is determined based on rotation speed of the motor and a torque instruction value. When switching from PWM wave voltage driving to square-wave voltage driving occurs, the voltage output of the power generator is reduced. When generated voltage V drops below a specified threshold voltage, PWM wave voltage driving is switched to square-wave driving.