1. A method for processing a contrast picture image of a semiconductor element comprising: a color grade number reducing processing that automatically reduces number of color grades of said contrast picture image of the semiconductor element, obtained from a device for analysis, in keeping with the contrast of said contrast picture image; an interconnect contrast extraction processing that classifies pixels contained in said contrast picture image, whose number of color grades has been reduced, in accordance with a preset contrast threshold value as reference, to extract an interconnect pattern fractionated into a plurality of number of contrasts; and a shift processing that removes noise contained in a contour portion of said interconnect pattern by shifting said contour portion; whereby an interconnect pattern contained in said contrast image of said semiconductor element obtained from said device for analysis is fractionated into a plurality of preset contrasts to be extracted.