An image signal processing device for correcting color difference signals includes a first correcting unit configured to set a correction amount for input color difference signals to “0” and generating output color difference signals when a colorless area containing the original point of a color difference space in which the two color difference signals are set as two intersecting axes, a first boundary line through which the inside and outside of the colorless area are partitioned, a suppression area which is nearer to the original point than the first boundary line and defined by a color difference suppression width, and a second boundary line through which the interior of suppression area and the inside area of the suppression area are partitioned are set in the color difference space and the values of the color difference signals are at the outside of the colorless area.