the monitor system 1 according to the present invention a panorama thermal image may be synthesized with the entire image forming a synthesized image the entire image displaying section 70 may display the synthesized image as is illustrated in fig6 seeing the synthesized image displayed in the entire image displaying section 70 the user can easily recognize any region detected as a thermal image in which a man exists in connection with the entire image thus the present invention enables the watchman to perceive the movement or change of any person in the area photographed from the luminance distribution shown in the thermal image therefore the watchman need not observe all images each input every time the camera scans the area his or her labor can be much reduced in addition the invention prevents the watchman from overlooking changes in the area the invention therefore helps to achieve very reliable surveillance if the monitor system 1 is used to perform surveillance at night the camera unit 2 provides dark entire images only from which the movement of any person cannot be perceived nevertheless any region in which a man exists can be identified with a specific luminance distribution in any thermal image obtained from the thermal camera 82 that detects the infrared rays emanating from any.