To provide an AC rotary machine control device which can superimpose the 5th order and the 7th order harmonic voltages on the AC voltage applied to the AC rotary machine by calculation processing of low processing load, and an electric power steering device provided with the same. An AC rotary machine control device performs middle voltage offset processing that adds offset value to middle voltage command when middle voltage command in three phase basic voltage commands is larger than vibration center voltage, and subtracts offset value from middle voltage command when middle voltage command is smaller than vibration center voltage.