A semiconductor chip is temporarily fixed on a circuit board by having a thermosetting adhesive film in between. A sealing resin film is provided with a mold release film, and a thermosetting sealing resin layer, which is laminated on the mold release film and has a film thickness 0.5 to 2 times the thickness of the semiconductor chip. The sealing resin film is arranged on the semiconductor chip so that the thermosetting sealing resin layer faces the semiconductor chip. Heat is applied to the side of the circuit board, while applying pressure to the sealing resin film from the side of the mold release film by using a rubber head having a rubber hardness of 5-100 to bond the semiconductor chip on the circuit board. After sealing the semiconductor chip with the resin, the mold release film is peeled.