Power supply apparatus

Two coils (61, 62) for electric power supply are arranged on a vest (31) covering a subject, where the coils are wound diagonally and symmetrically on the surface around the vest (31). Electric power is supplied to the coils (61, 62) through driver circuits (63-66) from a power supply unit in an external apparatus to pass electric current through the coils (61, 62). This causes magnetic fluxes in different directions to be produced so that they penetrate through the coils (61, 62), generating a non-directional magnetic field. As a result, electric power is efficiently supplied to a device to be introduced into the subject, such as a capsule-type endoscope.