A motor control device capable of providing an appropriate and most suitable motor current waveform, in order that efficiency and power factor for the motor is significantly improved and the high frequency and noise thereof are reduced. In an inverter type motor control circuit including a pulse width modulation waveform synthesis circuit by which a plurality of switching elements are controlled so as to obtain an A.C. power having a predetermined frequency, the pulse width modulation waveform synthesis circuit includes: memory circuit for storing a reference pulse waveform data series in order to control the switching elements; phase control circuit for controlling a starting stage of the reference pulse waveform data series which is read from the memory means; and modifying circuit for modifying and correcting a reference level of the motor control circuit so that a duty ratio of the reference pulse waveform data series is uniformly varied.