A mura detection device includes an XYZ coordinate system conversion unit which receives a photographed image of a display device and converts the photographed image into XYZ image data according to XYZ chromatic coordinates, a background image generation unit which generates background image data obtained by removing a part of the XYZ image data, a color difference calculation unit which generates color difference image data by comparing the photographed image and the background image data, and a mura data generation unit which calculates a color mura index value using the color difference image data.