A coil unit in which impact resistance is ensured and that has a magnetic body for heating prevention. The coil unit (the power receiving coil unit) includes a winding wire (the winding wire portion) and a magnetic body, wherein in the magnetic body, a plurality of individual pieces with two principle surfaces opposing in a thickness direction are disposed in rows and columns in a direction substantially orthogonal to the thickness direction, and the two principle surfaces are in a polygonal shape and all interior angles forming a polygon are obtuse angles (except for a right angle).