Disclosed is a capacitor cooling device which is mounted in a vehicle capable of being driven by power from an electric motor that is driven with a capacitor as the power source, and which is equipped with a cooling air generation unit that generates a cooling air for the purpose of cooling the capacitor and a flow volume control unit that controls the cooling air generation unit such that, of two modes, for which the recovery efficiency differs when recovered energy obtained from the electric motor during deceleration of the vehicle is recovered by the capacitor, a cooling air having a flow volume larger than the flow volume when the low-recovery rate mode is set is generated during deceleration of the vehicle when the high-recovery rate mode is set. Accordingly, a sufficient cooling air can be supplied to the capacitor during deceleration of the vehicle when the high-recovery rate mode is set for the recovered energy.