To provide a power source feeder effectively radiating heat inside a casing, a noncontact power transfer apparatus, and a joint supporting apparatus.

The power source feeder is provided with a power source feed part 35 inside a casing 31 to supply power, with non-contact electromagnetic induction effect. The power source feeder includes a heat-radiating plate 33 having the one surface placed in close contact with the power source feeding part 35 and a heat-absorbing material 34, provided between the heat radiating plate 33 and the casing 31 to have the property of changing into solid state and liquid state, at a specified temperature.