Abstract: An induction motor control apparatus for controlling the power factor at which an induction motor operates includes sensors and circuits for periodically detecting the effective (RMS) values of current and voltage supplied to the motor winding during a fixed number of cycles, e.g. one cycle, and multiplying these to obtain a value of apparent power of the motor, together with circuits for detecting the working power of the motor, with the power factor of the motor being thereby accurately obtained. The detected power factor is compared with an ideal value of power factor, to obtain an error amount that is applied to control the motor voltage. The ideal power factor is obtained by multiplying a designated value of power factor by a compensation amount that is determined in accordance with the motor load, thereby ensuring that stable operation of the motor is achieved even under the no-load condition.