PURPOSE: To prevent any irregular display on a display device by preventing any output from appearing at an output terminal corresponding to a broadcasting system not under reception at the signal converting and switching device equipped with output terminals containing terminals to output base frequency band signals corresponding to various broadcasting systems.
CONSTITUTION: At a signal converting and switching device 10 equipped with a function to respectively output a video signal Vd and audio signals Ld and Rd in the base frequency band of an NTSC signal to a video output terminal and an audio output terminal after executing any suitable conversion processing in the case of receiving the NTSC signal and equipped with an FM detection output terminal Fd to output the base frequency band signal in the case of receiving the NTSC signal and a MUSE signal, analog switches 14-17 are connected to the respective output terminals, the analog switches 14-16 are closed in the case of receiving the MUSE signals, the analog switch 17 is closed in the case of receiving the NTSC signal, and the respective output terminals are alternatively grounded. Therefore, in the case of receiving the MUSE signal or the NTSC signal, no irregular display is executed at the display device for the NTSC signal or the MUSE signal.