WIRELESS POWER SUPPLY DEVICE

In order to reduce a power transmission antenna and power receiving antenna of a wireless power supply device for supplying power underwater to a size suitable for an underwater mobile body and sensor, this underwater wireless power supply device wirelessly transmits energy by resonating at a frequency determined by the impedance of a power transmission antenna that transmits energy wirelessly in a good conductor medium , the impedance of a power receiving antenna which receives energy transmitted from the power transmission antenna , and the impedance of the good conductor medium . The power transmission antenna and the power receiving antenna have the multiple antenna coils , and at least one dielectric arranged between the multiple antenna coils , and the multiple antenna coils each has multiple laminated coils