A current value determination device provided with: a capacitor current computation unit for computing the capacitor current of a capacitor included in a high-voltage circuit that drives a motor, on the basis of the input voltage of an inverter included in the high-voltage circuit and the revolution speed of the motor; and a capacitor current determination unit for determining the value of capacitor current on the basis of the input voltage of the inverter, the revolution speed of the motor, the capacitor current computed by the capacitor current computation unit, and a prescribed model for determination.