It is an object of the invention to provide an apparatus for estimating a magnetic pole position of a motor in which the amplitudes of high-frequency currents can be adjusted.In the invention, a controlling apparatus for driving a motor (1-1) by a voltage source PWM inverter (1-2), and controlling a torque and speed, or torque, speed, and position of the motor has: means for switching over first means for producing an arbitrary phase difference in PWM carrier signals between respective two phases such as UV, VW, or WU of three or UVW phases, and second means for causing the phase difference between two phases such as V, VW, or WU of three or UVW phases to become zero; means for extracting high-frequency currents in a same frequency band as carrier signals generated by it, from estimated currents; and means (1-4) for estimating a magnetic pole position by using the extracted high-frequency currents.