A method and computer program for generating a capacitance value rule table, which simplifies generation of the capacitance value rule table for multilayer wiring having a complex dielectric constant structure are provided. In the method, construction data of wire adjacent to a wire of interest is extracted (S30), a common dielectric constant for a plurality of insulating film in the construction data is calculated (S32), and capacitance value rule table (F12) is created based on the common dielectric constant (s34).