A matching circuit and an antenna apparatus which, though small-sized, can be used in a radio apparatus which transmits and receives radio waves having a wide range of frequencies. A matching circuit includes an inductance element formed of a chip inductor connected in series with an antenna body, a first capacitance element formed of a trimmer capacitor, and a second capacitance element formed of a chip capacitor, which capacitance elements are connected between respective ends of the inductance element and a ground terminal, and thus in parallel to the antenna body. One end of the inductance element is connected to the power supply terminal of the antenna body, and the other end is connected to a power source for applying a voltage to the antenna body. The first capacitance element is connected between a ground and the connection point of the power supply terminal of the antenna body and the inductance element. The second capacitance element is connected between a ground and the connection point of the inductance element and the power source.