The present invention includes the steps of forming a first resin film uncured on a wiring substrate including a wiring pattern, burying an electronic parts having a connection terminal on an element formation surface in the first resin film uncured in a state where the connection terminal is directed upward, forming a second resin film for covering the electronic parts, obtaining an insulation film by curing the first and second resin films by heat treatment, forming a via hole in a predetermined portion of the insulation film on the wiring pattern and the connection terminal, and forming an upper wiring pattern connected to the wiring pattern and the connection terminal through the via hole, on the insulation film.