An antenna device (101) is configured from an antenna element (20) capable of transmitting and receiving high-frequency signals in a plurality of frequency bands, and an antenna matching circuit (50). The antenna matching circuit (50) is provided with an impedance converting circuit (30) connected to the antenna element (20) side, and a variable reactance circuit (40) connected to a power feeding circuit (10) side. The impedance converting circuit (30) includes a first inductance element (L1) and a second inductance element (L2) which are transformer coupled, and the variable reactance circuit (40) includes a reactance element connected in parallel or in series with a transmission/reception signal transmission path, and a switch (SW) for switching the connection state of the reactance element.
