A semiconductor module made from a compound semiconductor or diamond and loaded with high performance power semiconductor devices can be obtained at low cost. In a semiconductor module, four (semiconductor chips) of same specifications are arranged in array, two longitudinally and two transversally, on a single lead frame. Achieving a high yield of manufacturing diode chips and reducing the unuseful area of diode chips need to be satisfied at the same time to obtain such a semiconductor module at low cost. The use of an index, which is the product of the yield YDie of manufacturing chips and the active region area ratio RA is effective for determining them. Thus, semiconductor modules can be obtained at a high yield by selecting a chip size that makes the index close to a peak value depending on the crystal defect density of a wafer to be used.