A two-dimensional sensor is installed inclining at a predetermined angle to a moving direction of a stage on which an object to be inspected is mounted and, in synchronism with the movement of the stage, a picked up image is rearranged so that there can be obtained an image in high-density sampling with a picture-element size or less of the two-dimensional sensor with respect to a wafer. A gate stack is formed over a semiconductor substrate comprising a gate oxide layer, a conducting layer, and a first insulating layer. The first and second connectors have flexible arms that are oriented 90 degrees apart, permitting the connectors to slip in perpendicular directions in their respective receiving holes, thus providing improved tolerance and adjustability during installation.