An integrated antenna device includes: a multiplexing processing portion for multiplexing received signals received at antennas of mutually different signal systems; a serial communication portion for outputting a multiplex signal to the outside and for receiving a control signal from the outside; a power-feeding switch for individually controlling power feeding of tuner units on the basis of the received control signal; and a pseudo-signal generating portion for generating a pseudo-signal that simulates a signal input to the multiplexing processing portion. The multiplexing processing portion uses the pseudo-signal generated at the pseudo-signal generating portion instead of a received signal corresponding to a tuner unit that is stopped from being fed power by the power-feeding switch.