An apparatus analyzing electromagnetic waves radiated from an appliance using a net pattern of the appliance and having a coordinates data extracting unit extracting, from net pattern information, coordinates data defining the coordinates of each of terminal points of a plurality of segments constituting the net pattern; and a smoothing unit for dividing the net pattern, based on the extracted coordinates data, into plural object sections, each of a length not greater than a predetermined maximum length, and smoothing the net pattern for each object section, by replacing plural segments in each object section with a single, or a plurality of, straight lines smaller in number than the number of the segments. The electromagnetic field intensity of the electromagnetic waves is calculated on the basis of coordinates data for which smoothing is completed.