There has been a problem of displacement of luminance and chromaticity among multiple screens due to a temperature change and a temporal change of a light source of the screen. The present invention provides a multi-screen display device including a plurality of image display devices, in which one master device and one or a plurality of slave devices communicable with the master device are included, each of the image display devices is provided with a DMD that modulates light of a light source, a screen that projects an image by modulated output light of the DMD, and an RGB luminance sensor that detects luminance of light from the DMD in an off-state, to output a luminance detection value, the master device is provided with a setting part that sets a luminance setting value unified among the plurality of image display devices based on a value in accordance with the luminance detection values, and each image display device is further provided with a luminance/chromaticity corrector that controls luminance/chromaticity of an image displayed on the screen based on the luminance setting value.