In a digital broadcasting receiver, an identification information of the image or audio signal detected from the received digital information, and an identification information stored in an identification information memory means are compared one after another. The image/audio mute means is controlled not to output a disordered image/audio signal on the basis of the comparison result. On the basis of the comparison result, the viewer is informed by the identification information output means that resolution/quality of the received image/audio signal is changed. The identification information showing the image resolution and audio quality is inserted into digital information, and the digital information with the identification information is transmitted in a digital broadcasting transmitter.