There is provided a method for generating a pattern. A pattern is generated by selecting a cell from a cell library including a plurality of cells, adding, to the interior of the selected cell, a second pattern different from a first pattern of the selected cell, performing a first optical proximity correction (OPC) onto the pattern of the selected cell including the first pattern and the second pattern, performing a second optical proximity correction onto a pattern of a plurality of cells in which the selected cell including first pattern and second pattern, which have been subjected to the first optical proximity correction, and another of the cells are proximately arranged and generating the pattern including the patterns of the plurality of cells which have been subjected to the second optical proximity correction.