A power transmission device of this noncontact power supply apparatus has a transmission coil for supplying power to a power reception device, and a power supply circuit that supplies AC power to the transmission coil. A power reception device of the noncontact power supply apparatus has a reception coil for receiving power from the power transmission device, a variable capacity circuit that is connected to the reception coil in parallel and that can adjust capacitance, a resonance circuit that resonates with a frequency corresponding to the inductance of the reception coil and the capacitance of the variable capacity circuit, a voltage detection circuit that detects an output voltage from the resonance circuit, and a control circuit that controls the capacitance of the variable capacity circuit according to the output voltage.