PURPOSE: To provide an electric vacuum cleaner wherein noise component generated by an electric motor, etc., cane surely be decreased.

CONSTITUTION: The phase of a signal on the number of rotation of an electric motor 2 detected by means of a rotational sensor 4 is controlled by a delay circuit 6 and only the rotational component of this phase-controlled signal of the number of rotation is extracted by a low pass filter 7 and the amplitude of an output signal of the low pass filter is adjusted by an amplifier 8 and a speaker 9 is driven by this amplitude-adjusted signal and a control sound interfering to the rotating sound and noises being integer-fold of the number of rotation of the electric motor 2 is output thereby to decrease the noises.