A method of manufacturing a semiconductor device, including the steps of: acquiring information on a graphic composing a physical layout of a semiconductor integrated circuit; carrying out calculation for a transferred image in the physical layout; carrying out calculation for a signal delay based on the physical layout, and obtaining a wiring not meeting a specification having the signal delay previously set therein; and setting a portion into which a repeater is to be inserted based on at least one result of results obtained from the information on the graphic and calculation for the transferred image, respectively, with respect to the wiring not meeting the specification.