s c and then semiconductor modules are manufactured using as a desired substrate s that of the semiconductor module with a greater fom m consequently lower cost semiconductor modules can be provided in addition to performance satisfaction being achieved if the semiconductor module process includes a comparison step through which comparison is made between the fom m of the semiconductor module of using the silicon substrate s s and that of using the silicon carbide substrate s c and a selection step that selects through the comparison step the substrate s with a greater fom m as a desired substrate s and if semiconductor chips are manufactured by forming a semiconductor element such as diode mosfet and igbt on the substrate s selected through the selection step and also if a semiconductor module is manufactured using a packaging step that mounts and interconnects a plurality of semiconductor chips achieved by way of the element formation step to then house the plurality thereof in a package thus this manufacturing process leads to enhancement of market price competitiveness resulting in such modules being commercially advantageous note that while the present embodiment is described using the example of the inverter as the objective product it should be understood of course that the present invention is not limited to the inverter but applicable to other products such as a converter a pfc power factor control circuit and a brake circuit as well note again that although the present embodiment is described using an example of the silicon substrate s.