Abstract: It is intended to provide a non-contact transformer which simplifies attachment work, causes no sound of rubbing between wires or resistance during steering wheel manipulation, increases the transmission efficiency, and can be manufactured easily by virtue of a minimized warp occurring during manufacture of a core. A non-contact transformer is provided that includes two disc-shaped magnetic cores (19) each having at least one concentric and radial groove (21), and a magnetic sleeve (25) having a cylindrical shape or a pot shape having an opening at the center of the bottom surface. The two magnetic cores are opposed to each other with a predetermined distance left therebetween in a space enclosed by the magnetic sleeve. A wining (23) of wire is accommodated in the at least one concentric groove. Each of the magnetic cores is a combination of a plurality of fan-shaped partial cores (27) to be formed in a disc shape.