The present invention has a purpose to provide an inspection method of inclination of an IC in order to decide a position of IC speedily and precisely without the image information of binarized images or an image of each pin.
An inspection method of inclination of an IC for arranging sides of it approximately in parallel to X-axis and Y-axis comprising steps of: inputting image of an IC; defining a plurality of checking areas including open ends of a plurality of IC pins at predetermined positions in the image; generating a density projection along a direction parallel to IC pins expected in each checking area; regarding a position of the maximum value of a primary differential as the open ends of the IC pins; defining a representative point at a predetermined position on a line along the open ends; and calculating inclination of an IC according to the inclination of a reference line substantially connecting the representative points of the checking areas.