A layout generating apparatus and a layout generating method to obtain high-quality optimization results (improvements in operation speed and the degree of integration and a reduction in power consumption). Specifically, there are disposed input data storage part (1), before-compaction layout generating part (2), first compaction processing part (3), second compaction processing part (4), third compaction processing part (5), mid-course-processing data storage part (6), channel-width optimization processing part (7), layout optimization processing part (8), output data storage part (9), and control part (10). The operations of all the mentioned parts are controlled by the control part (10).