PURPOSE: To obtain a high gain in a comparatively wide frequency range.

CONSTITUTION: An antenna impedance matching circuit is formed by connecting matching coils L5 and L6 in series, and a diode D2 is connected to the coil L6 in parallel, and a voltage of high or low level is impressed from a selection signal generating part M on the anode side of the diode D2. When tuning with an upper side frequency in the reception band of AM broadcast is taken, a high level voltage is outputted from the part M, and the diode D2 is energized, then, the coil L6 is short-circuited. Thereby, the matching circuit is formed with only the coil L5, and impedance matching is taken at an upper frequency band. While, when tuning with a lower side frequency is taken, a low level voltage is outputted from the part M, and the diode D2 is not energized, and the matching circuit is formed by the series circuit of the coils L5 and L6, and the impedance matching can be taken it a lower side frequency band. In such a way, since the impedance is taken by bisecting a band into the upper and lower frequency band areas, the high gain can be obtained in the comparatively wide frequency range.