There is provided a non-contact power transmission apparatus which can supply stable power from a power transmitting side to a power receiving side even if a load is changed. The power transmission apparatus transmits power from a power transmitting device to a power receiving device in a non-contact manner. The power transmitting device includes a series circuit which is connected to a direct-current power source, and includes a parallel resonance circuit including a first capacitor and a first inductor, and a switch element, a drive source to drive on or off the switch element, and a first series resonance circuit connected to a connection point between the parallel resonance circuit and the switch element and including a second inductor, a second capacitor and a power transmission coil. The power receiving device includes a second series resonance circuit including a power receiving coil paired with the power transmission coil and a third capacitor connected in series to the power receiving coil, and a rectifying circuit to rectify a voltage generated in the second series resonance circuit and to supply the voltage to a load circuit.