NON-CONTACT POWER SUPPLYING DEVICE AND NON-CONTACT POWER SUPPLYING METHOD

A non-contact power supplying device includes a power-receiving resonating means set to have a predetermined resonant frequency; a power-feeding resonating means set to have a resonance frequency equal to the predetermined resonant frequency; an oscillating means configured to input an alternating-current power into the power-feeding resonating means; an impedance detecting means configured to detect impedance within a predetermined frequency range as viewed from a power-feeding side; and a frequency-variable means configured to set a frequency of the alternating-current power. The oscillating means is configured to supply electric power to the power-receiving resonating means by producing a resonance between the power-receiving resonating means and the power-feeding resonating means. The frequency-variable means is configured to set the frequency of the alternating-current power in accordance with a value of the impedance detected by the impedance detecting means within the predetermined frequency range.