A device for controlling a motor (MG1, MG2) mounted on an electrically powered vehicle, comprising: a motor command operation unit (300, 305) for generating a control command (Vu, Vv, Vw) for a voltage or a current to be supplied to said motor from a power converter (210, 220) configured to include at least one switching element; and a carrier generation unit (360, 365) for generating a carrier signal used for controlling said power converter; characterized by a carrier frequency control unit for such control that frequencies of a plurality of carrier signals ( 160, 160) generated by said carrier generation unit are caused to fluctuate, that is to change as time elapses, within a first frequency range with a prescribed frequency being defined as a center while a vehicle speed of said electrically powered vehicle is higher than a prescribed speed and the frequencies are caused to fluctuate, that is to change as time elapses, within a second frequency range with said prescribed frequency being defined as the center while said vehicle speed is lower than said prescribed speed; and a pulse width modulation unit (310, 315) for controlling on and off of said switching element in said power converter based on comparison between said control command from said motor command operation unit and said carrier signal from said carrier generation unit, equipment mounted on said electrically powered vehicle forming a plurality of mechanical oscillation systems which generate sound as a result of oscillation by electromagnetic oscillation originating from said carrier signal, and said first and second frequency ranges being set such that sound generated from said plurality of mechanical oscillation systems when the frequency of said carrier signal fluctuates within said second frequency range is louder than sound generated from said plurality of mechanical oscillation systems when said carrier frequency fluctuates within said first frequency range, wherein said first and second frequency ranges are set such that at least any resonant frequency (frm) of said plurality of mechanical oscillation systems is out of said first frequency range and within said second frequency range. a motor command operation unit (300, 305) for generating a control command (Vu, Vv, Vw) for a voltage or a current to be supplied to said motor from a power converter (210, 220) configured to include at least one switching element; and a carrier generation unit (360, 365) for generating a carrier signal used for controlling said power converter; characterized by a carrier frequency control unit for such control that frequencies of a plurality of carrier signals ( 160, 160) generated by said carrier generation unit are caused to fluctuate, that is to change as time elapses, within a first frequency range with a prescribed frequency being defined as a center while a vehicle speed of said electrically powered vehicle is higher than a prescribed speed and the frequencies are caused to fluctuate, that is to change as time elapses, within a second frequency range with said prescribed frequency being defined as the center while said vehicle speed is lower than said prescribed speed; and a pulse width modulation unit (310, 315) for controlling on and off of said switching element in said power converter based on comparison between said control command from said motor command operation unit and said carrier signal from said carrier generation unit, equipment mounted on said electrically powered vehicle forming a plurality of mechanical oscillation systems which generate sound as a result of oscillation by electromagnetic oscillation originating from said carrier signal, and said first and second frequency ranges being set such that sound generated from said plurality of mechanical oscillation systems when the frequency of said carrier signal fluctuates within said second frequency range is louder than sound generated from said plurality of mechanical oscillation systems when said carrier frequency fluctuates within said first frequency range, wherein said first and second frequency ranges are set such that at least any resonant frequency (frm) of said plurality of mechanical oscillation systems is out of said first frequency range and within said second frequency range.