A semiconductor module in which a plurality of kinds of semiconductor devices having different heat generating amounts in being operated are mixedly present, heat conducting sheets are interposed between a module main body mounted to a board and outer faces of the semiconductor devices, and heat radiating plates are mounted thereto by covering outer faces of the semiconductor devices over two pieces or more of the semiconductor devices, wherein the heat conducting sheet having a heat conductivity higher than a heat conductivity of the heat conducting sheet used for the semiconductor device having a heat generating amount smaller than a heat generating amount of the semiconductor device is used for the semiconductor device having a large heat generating amount in the semiconductor devices.