A semiconductor module manufacturing method includes a step of bonding a semiconductor wafer, which has a plurality of semiconductor elements each of which has an element electrode formed thereon, on an expansible first insulating resin layer; a step of dicing the semiconductor wafer; a step of expanding the first insulating resin layer to widen a gap between semiconductor elements; a pressure-bonding step of pressure-bonding a metal plate whereupon an electrode is arranged and the semiconductor elements with the widened gaps in between, by having a second insulating resin layer in between, and electrically connecting the electrode and the element electrodes; a step of forming a wiring layer which corresponds to each semiconductor element by selectively removing the metal plate and forming a plurality of semiconductor modules connected by the first insulating resin layer and the second insulating resin layer; and a step of separating the semiconductor modules by cutting the first insulating resin layer and the second insulating resin layer.