To display a stored image with same image quality at a supervised point/supervisory point together with display of a real time image from the supervised point at the supervisory point.

A video signal from a video camera 4 is sent from a supervised point 1 to a supervisory point 3 via an image coder 5 and an ISDN network 2. The video signal is displayed on the screen of a monitor television receiver 7 via an image decoder 6 and stored sequentially in a digital storage section 11 as it is and then reproduced later at any time and displayed on the screen of the monitor television receiver 7 via the image decoder with the same image quality.