To quickly retrieve, transfer and watch monitored images in a supervisory system that is equipped with a monitoring camera.

A supervisory system consists of at least one camera 121 to 124 that monitors an images that corresponds to a supervisory area in a supervisory object facility, a controller 100 and a supervisory device 200 that is located far from the supervisory object facility and connected to the controller 100 through a communication line 300. The controller 100 is provided with a clock means 106 that outputs a time signal and storing part 103 which stores an image signal, a camera number signal and a time signal. When the image of a specific time of a specific camera is necessary to be watched, it is fetched by retrieving through needed data such as the camera number, the time, etc.