To provide a system which has high operation efficiency and shortens the time needed to determine a design rule by automating processes up to the determination of the design rule.

The system is equipped with an L/S pattern automatic generation part 1 which automatically generates an L/S pattern prescribed by line width and space width, an optical simulation part 2 which performs optical simulation according to the L/S pattern, a finish prediction part 3 which predicts the size (finish size) of a pattern formed on resistance according to the result of the optical simulation, an L/S matrix database structuring part 4 which generates an L/S matrix according to the finish prediction result and structures data used for the L/S matrix generation in the form of a database, and a design rule generation part 5 which generates a design rule from the L/S matrix.