In an impedance matching circuit, first to fourth inductors are formed by a conductor pattern of a coil shape, and a fifth inductor is formed by a conductor pattern of an unwound shape. The first inductor and the third inductor are respectively formed in different layers of a substrate and are arranged in such a relationship as to have coil openings overlapping each other. Moreover, the second inductor and the fourth inductor are respectively formed in different layers of the substrate and are arranged in such a relationship as to have coil openings overlapping each other. Two coils interposing the mounting position of the RFIC are in a 180° rotational symmetry relationship.