a display screen inspection method according to the present invention takes a display screen of a display device as an inspection subject and makes decisions on defects of the display screen . the method includes performing a separation between display operating portions and display non - operating portions of the inspection subject present in a gray image from image data of individual pixels of the gray image obtained by picking up an image of the inspection subject , selectively extracting image data of only proper display operating portions and compressing the image data to be inspected for defects , and inspecting the selectively extracted image data for any defects .