A control section of an IRD sends an identification start request to a digital bus via a digital input/output terminal. The control section generates an identification display message by controlling an identification display message generation section, makes a superimposition section superimpose the identification display message on an analog video signal, and outputs a resulting signal via an analog output terminal. An information input apparatus allows a user to identify an input terminal connected to the output terminal of the IRD among a plurality of input terminals of the self apparatus by reproducing the identification display message and presenting it to the user.