[Problem] In a pseudo-current source inverter which drives a motor at a high speed, a current phase adjustment is assured and facilitated to perform a field-weakening control or suppress a terminal voltage saturation at a time of the high-speed motor drive.[Means For Solving Problem]A phase advance correction is carried out for a magnetic flux phase information from which a 120 degree conduction pattern is obtained with a motor terminal voltage as a reference phase. The phase advance correction includes the correction of differentiating the terminal voltage detection signals of the motor, the adjustment of enlarging the phase advance correction quantity in a case where the motor load current is large, and delays the gate signals of the 120 degree conduction pattern in accordance with the speed estimation value through a delay counter and carries out the phase advance correction as the rising edge timing of the subsequent gate signal at the subsequent step phase. Furthermore, the error correction is carried out for the phase advance correction quantity in accordance with a variation tendency of the speed estimation value and a detection value of a direct current of the inverter.