A motor control device that controls a three-phase electric motor (two-system motor) that has two-system multi-phase motor coils, the motor control device comprising: a pulse width modulation count computation unit that computes a PWM count (Cu 1, Cv 1, Cw 1, Cu 2, Cv 2, Cw 2) for each phase in each system in each current control cycle (Ta) that includes a plurality of PWM cycles (Tc); and a common mode noise reduction unit including a PWM count setting unit that sets (S1, S2) the PWM count for each phase in each system in a current control cycle (Ta), said PWM count being provided from the PWM count computation unit, as a PWM count in each PWM cycle (Tc) in the current control cycle (Ta) for the corresponding phase in the corresponding system; wherein the common mode noise reduction unit changes the PWM count, set by the PWM count setting unit, in a PWM cycle (Tc) for at least one phase in one of the two systems such that a current that flows through a stray capacitance (C3, C4) because of an output voltage for one phase in the other system is canceled out with a current that flows through the stray capacitance because of an output voltage for the at least one phase in the one system in at least one PWM cycle (Tc) in the current control cycle (Ta), wherein the common mode noise reduction unit includes a PWM count change unit that changes the PWM count for the at least one phase in the one system, of a PWM signal in each PWM cycle (Tc) in the current control cycle (Ta) for each phase in each system, such that an output voltage waveform for the at least one phase is a waveform obtained by inverting an output voltage waveform for the one phase in the other system in the at least one PWM cycle (Tc) without changing a total value of PWM counts for the at least one phase in the current control cycle (Ta), and wherein the common mode noise reduction unit changes the PWM counts in a PWM cycle (Tc) for two phases (Cv 1, Cw 1) in the one of the two systems, wherein by changing the PWM counts the PWM count for the one phase in the other system in each PWM cycle (Tc) coincides with the PWM count for either the one (Cv 1) or the other (Cw 1) of the two phases in the one system. a pulse width modulation count computation unit that computes a PWM count (Cu 1, Cv 1, Cw 1, Cu 2, Cv 2, Cw 2) for each phase in each system in each current control cycle (Ta) that includes a plurality of PWM cycles (Tc); and a common mode noise reduction unit including a PWM count setting unit that sets (S1, S2) the PWM count for each phase in each system in a current control cycle (Ta), said PWM count being provided from the PWM count computation unit, as a PWM count in each PWM cycle (Tc) in the current control cycle (Ta) for the corresponding phase in the corresponding system; wherein the common mode noise reduction unit changes the PWM count, set by the PWM count setting unit, in a PWM cycle (Tc) for at least one phase in one of the two systems such that a current that flows through a stray capacitance (C3, C4) because of an output voltage for one phase in the other system is canceled out with a current that flows through the stray capacitance because of an output voltage for the at least one phase in the one system in at least one PWM cycle (Tc) in the current control cycle (Ta), wherein the common mode noise reduction unit includes a PWM count change unit that changes the PWM count for the at least one phase in the one system, of a PWM signal in each PWM cycle (Tc) in the current control cycle (Ta) for each phase in each system, such that an output voltage waveform for the at least one phase is a waveform obtained by inverting an output voltage waveform for the one phase in the other system in the at least one PWM cycle (Tc) without changing a total value of PWM counts for the at least one phase in the current control cycle (Ta), and wherein the common mode noise reduction unit changes the PWM counts in a PWM cycle (Tc) for two phases (Cv 1, Cw 1) in the one of the two systems, wherein by changing the PWM counts the PWM count for the one phase in the other system in each PWM cycle (Tc) coincides with the PWM count for either the one (Cv 1) or the other (Cw 1) of the two phases in the one system.