To provide an automatic wiring system which enables wiring in consideration of wiring branching specifying branch points of a wire and the automatic addition of properties at the time of connection information generation and can confirm the consitency of connection at the time of connection verification to original data.

This automatic wiring system for an integrated circuit layout data automatic generation system has a step 400 wherein wiring division macros are generated after circuit designing in an ideal state wherein the wiring impedance, etc., of a previous process is not considered, a step 301 wherein connection information is generated in consideration of wiring division based upon connection information including the wiring division macros, a step 302 wherein elements are arranged in layout data generation by connection information generation in consideration of the wiring division, a step 500 wherein wiring division macrocells are generated from layout data after the element arrangement is completed, and a step 600 wherein the wiring division macrocells are arranged.