When a multi-directional antenna is connected to a digital TV broadcast signal receiver, the digital TV broadcast signal receiver measures a term suitable for switching or changing an effective signal receiving direction of the multi-directional antenna corresponding to kind or specification of the multi-directional antenna. Control signals are outputted at an interval suitable for switching or changing the effective signal receiving direction of the multi-directional antenna corresponding to the measured term so as to switch the effective signal receiving direction of the multi-directional antenna to an optimum signal receiving direction of a channel chosen by a user. Consequently, it is possible to shorten a term necessary for switching or changing the effective signal receiving direction of the multi-directional antenna to the optimum signal receiving direction of the channel chosen by the user.