An image signal processing apparatus includes an image signal input unit; a gradation decrease evaluation device that evaluates a decrease in gradation within a certain area in image signals; a gradation loss evaluation device that evaluates a degree of gradation loss within a certain area in image signals; an image signal correction device that performs signal level correction processing on image signals and outputs the processing result; and an image signal correction control device that controls strength of correction by the image signal correction unit, using both the gradation decrease evaluated value which is output by the gradation decrease evaluation device and the gradation loss evaluated value which is output by the gradation loss evaluation unit.