A method of quickly and accurately inspecting the stitching accuracy at which
regions
of a lithographic pattern are stitched at boundaries. The numerous regions of the
lithographic pattern are exposed or delineated, one at a time. Inspected regions
are scanned with a charged-particle beam to detect secondary electrons. The obtained
signal is stored as an inspected image in an image memory, together with positional
data about the inspected regions. After completion of acceptance of images from
all the inspected regions, the inspected image is compared with a separately prepared
reference image by an image processing unit. Pattern elements in the inspected
regions corresponding to the reference image are extracted. Deviations at field
boundaries or the like can be detected from the relative positions of these pattern
elements, if any.
