COIL UNIT

A coil unit includes: a coil which transmits power to a power receiving device in a non-contact manner; a casing which accommodates the coil; and a core member that is inserted into an air core region of the coil and penetrates the casing to protrude outward, wherein the core member includes a frame-shaped wall portion which is disposed in the air core region and a lid portion which opens and closes an opening end of the wall portion.