Abstract: An apparatus for controlling a PWM controlled inverter adapted to effect the waveform control of the inverter output voltage in accordance with the memory content of ROM in which instantaneous output voltage data are memorized. This control apparatus comprises a ROM in which the instantaneous output voltage outputs thereof in the PWM control are memorized, and in which the number of addresses within a predetermined electrical angle section is set to a fixed value irrespective of the number of switching times within the electrical angle section, an electrical angle counter in which duration corresponding to the duration time data read from the ROM is set, an address counter responding to the count-up of the electrical angle counter to advance the read address of the ROM, and a controller for controlling the output voltage of the inverter in accordance with an instantaneous output voltage corresponding to the instantaneous output voltage data read from the ROM.