A non-contact power supply apparatus includes a transmission-side pad, a transmission-side resonant circuit, a reception-side pad, a reception-side resonant circuit, a power transmission circuit, a power reception circuit, and a control circuit. The control circuit controls an alternating-current voltage supplied to the transmission-side pad and an alternating-current voltage supplied to the power reception circuit, so that a power factor of the alternating current supplied from the power transmission circuit to the transmission-side pad connected to the transmission-side resonant circuit and direct-current power supplied from the power supply circuit to an on-board battery are respectively set to target values. As a result, change in power factor can be suppressed even when the coupling coefficient of the transmission-side pad and the reception-side pad changes, and predetermined electric power can be transmitted.