A magnetic core 47 to be housed in a coil bobbin 57 is split along a coil-axis intersecting direction Y into a plurality of split magnetic cores 47a, the coil-axis intersecting direction Y intersecting a coil axis direction X, and a clearance C extending along the coil axis direction X is provided between the plurality of split magnetic cores 47a. In each clearance C, a protrusion 51a protruding upward from a core base 51 is inserted and arranged to ensure sufficient rigidity. Providing the clearances C reduces the entire weight of the magnetic core 47 and also ensures a large coil width in the coil-axis intersecting direction Y. By ensuring a large coil width, alignment between a power-transmission-side coil 11 and a power-reception-side coil 13 becomes easier.