1. A pattern inspection apparatus for inspecting a pattern to-be-inspected by using an image of said pattern to-be-inspected and data for fabricating said pattern to-be-inspected, said pattern inspection apparatus comprising: an image generation device configured to generate a first image of a pattern in a standard semiconductor device and a second image of said pattern to-be-inspected; and a memory storing a plurality of machine readable instructions that when executed perform the steps of: (a) storing into said memory, a reference pattern generated from said data for fabricating said pattern to-be-inspected; (b) storing into said memory, at least part of said first image of said pattern in said standard semiconductor device; (c) detecting first edges within said first image using said reference pattern; (d) storing into said memory, a reference contour obtained from said first edges; (e) storing into said memory, at least part of said second image of said pattern to-be-inspected; (f) detecting second edges within said second image using said reference pattern; and (g) comparing said second edges to said reference contour to identify a defect.