Compacting a wiring layout of semiconductor integrated circuit having at least two metal layers in which two first layer wires of the same wiring are originally arranged at different locations and connected together by a second layer wire. First layer wires of other wiring are identified that interfere with a line extending from one of the two first layer wires and forms an enlarged area between the obstructed first layer wired and the interfering first layer wire. Next, the other one of the two first layer wires is shifted to the enlarged area to be aligned along the same line with the obstructed first layer wire. Then, the second layer wire which previously connected the two first layer wires is deleted.