A tuner circuit according to the invention includes two AGC control units
supplying AGC voltages V1 and V2 to an AGC amplifier, respectively. When
the AGC voltage V1 is higher the AGC voltage V2, a voltage on a cathode
of a diode becomes high, and the diode 11 is turned off. When the AGC
voltage V2 is higher than the AGC voltage V1, a voltage on an anode of
the diode becomes high, and the diode 11 is tuned on. Therefore, in the
case of an ordinary signal level, the AGC voltages establish a
relationship of, and the AGC voltage V2 performs the control. When an
excessively large disturbing signal is input, the AGC control unit
controls the AGC amplifier to suppress deterioration of performance.