To view messages which are simultaneously transmitted from the outside while the users view a broadcast program or contents recorded in the video recording device such as video tape recorder.

For compositing the picture of a commercial or the like at a specified channel by synthesizing the picture with only the video signal of the specified channel of a broadcast signal, a television message board is constituted in the following. In a video switch device, a fourth video signal inputted from a channel on a first broadcast signal received from an antenna or the like or from a video recording device is selected as a video signal corresponding to the specified channel and it is outputted to a computer. In the computer, the video signal is composited with the previously generated picture and it is outputted as the video signal. The video signal outputted from the computer is inputted and the video signal corresponding to the specified channel is modulated again. It is mixed with the broadcast signal of the other channel and it is outputted again as the broadcast signal.