A loop antenna includes a dielectric substrate taking a cuboid form, and a loop part composed of a metal that covers two pairs of facing surfaces of the dielectric substrate. The loop part is formed by leaving a blank portion at the center of one surface of the pair of facing surfaces having a wider area. In the blank portion, a feeding point to an LSI chip and a capacitance part connected to the loop part in parallel to the feeding point are formed. The capacitance part is provided to compensate for an internal capacitance of the LSI chip so that a small LSI chip matches the antenna. A convex part having a length is arranged with a gap within a corresponding concave part to form a large capacitance.