A power supply apparatus supplies power to a body-insertable apparatus from outside a subject. The body-insertable apparatus is introduced into the subject and obtains intra-subject information. The power supply apparatus includes a first electric cable which is wound around a circumferential surface of a garment and forms a coil, the garment covering the subject, the coil having a non-directionality at a time of power supply; and a power supply unit which supplies power to the body-insertable apparatus in a contactless manner through the coil.