A fourth strip conductor (24) and a seventh strip conductor (27) are formed at a predetermined height (H1) from the top surface of a dielectric substrate (10). The fourth strip conductor (24) and the seventh strip conductor (27) are substantially parallel to each other. A first antenna element (12) operates as a loop antenna that resonates at the wavelength ?h. This antenna device (100) operates as an inverted-F antenna that resonates at the wavelength ?l.
