To obtain a system with an enhanced operability where emphasis is placed on monitoring at night by displaying a video image from a 1st camera group on a 1st monitor and displaying a video image from a 2nd camera group on a 2nd monitor at daytime respectively and displaying the video image from the 1st camera group selected optionally on the 1st and 2nd monitors respectively at night.

A control operation section 6 is operated to control a matrix video switcher 3 as in the conventional systems in daytime so as to select N sets of video signals from an optional camera requiring monitoring in a 1st camera group 1. Then a 1st N division display 41 divides the video signals into N images and they are displayed on a 1st monitor 51. N sets of video signals are selected and outputted from an optional camera requiring monitoring from a 2nd camera group 2 and a 2nd N division display 42 divides the signals into N images. At night, an image recognition device 7 recognizes night and the video signals selected and preset are automatically displayed on the monitors 51, 52.