A receiver device for receiving incoming radio waves by using a plurality
of antennas, which is capable of improving the maximum input sensitivity
is provided. In the receiver device, a switching unit switches to an
antenna having the lower antenna gain as a new receiving antenna on the
precondition that when receiving incoming radio waves by one particular
antenna currently set as the receiving antenna, if a reception level of
this particular antenna becomes a level close to the maximum input
sensitivity of a signal processing unit, then the reception condition is
satisfactory. Consequently, it is possible to improve the maximum input
sensitivity and forestall the occurrence of waveform distortion and the
like.