To conduct verification of a pattern design in consideration of a pattern density.

In a step ST4, a first parameter (contour data) is extracted from the data in the pattern design, the first parameter is converted to a second parameter (the parameter obtained by dividing a plane area by an effective gate area after resizing +Xr) which is added in the electrification in response to the pattern density, and the degree of easiness in electrification is evaluated. Alternatively, a side area is extracted as the first parameter and it is determined whether a wiring layer matches the condition that the area of the dense part where patterns approach one another is equal to or more than a given area, or the like, and if the result of the determination matches it, the evaluation is made. Subsequently in a step ST5, the pattern of conductive layers is changed on the basis of the evaluated result.