1. A method of inspecting a semiconductor device, the method comprising: providing a substrate, on which a mold layer with a plurality of mold openings is provided; milling the mold layer in a direction inclined at a predetermined angle with respect to a direction normal to a top surface of the substrate, such that an inclined cutting surface exposing milled mold openings is formed, the milled mold openings including first milling openings along a first column extending in a first direction and having different heights; obtaining image data of the inclined cutting surface, the image data including first contour images of the first milling openings; and obtaining a first process parameter, which represents an extent of bending of the mold openings according to a distance from a top surface of the substrate, using positions of center points of the first contour images.