1. A semiconductor inspection system comprising: an inspected image acquisition unit configured to acquire an inspected image by irradiating a sample with a charged particle beam; a first contour line extraction unit configured to extract a first contour line from the inspected image; a second contour line extraction unit configured to extract a second contour line from a reference image corresponding to the inspected image; a distance image creation unit configured to create a reference distance image by providing pixel information to a plurality of pixels, including pixels corresponding to the second contour line and pixels surrounding the pixels corresponding to the second contour line, each of the plurality of pixels being provided with pixel information according to its distance from one of the pixels corresponding to the second contour line; a positions adjustment unit configured to align the first contour line with the reference distance image; a collation unit configured to collate the first contour line and the reference distance image aligned by the position adjustment, and provide pixel information to pixels of the first contour line based on the pixel information provided to corresponding pixels in the reference distance image, and a determination unit configured to calculate a size of a region defined by a portion of the first contour line that is not located at a predetermined position based on the pixel information provided to pixels of the first contour line.