In an interface unit, a shield layer includes an aperture through which magnetic flux generated by a power feeding coil of an antenna passes. Since the antenna is smaller than the shield layer, the aperture is much smaller than the shield layer. Thus, noise constituted by electromagnetic waves that travel from inside to outside of a computer via an aperture provided in an upper surface cover is blocked. During communication, the antenna and the shield layer are electromagnetically coupled to each other, and the shield layer defines and functions as an antenna. This allows proper communication with a communication target.