equipment extracts components of spatial frequency that need to be evaluated in manufacturing a device or in analyzing a material or process out of edge roughness on fine line patterns and displays them as indexes . the equipment acquires data of edge roughness over a sufficiently long area , integrates a components corresponding to a spatial frequency region being set on a power spectrum by the operator , and displays them on a length measuring sem . alternatively , the equipment divides the edge roughness data of the sufficiently long area , computes long - period roughness and short - period roughness that correspond to an arbitrary inspection area by performing statistical processing and fitting based on theoretical calculation , and displays them on the length measuring sem .