A substrate and a semiconductor chip are connected by means of flip-chip interconnection. Around connecting pads of the substrate and input/output terminals of the semiconductor chip, an underfill material is injected. The underfill material is a composite material of filler and resin. Also, a first main surface of the substrate, which is not covered with the underfill material, and the side surfaces of the semiconductor chip are encapsulated with a molding material. The molding material is a composite material of filler and resin. An integrated body of the substrate and the semiconductor chip, which are covered with the molding material, is thinned from above and below.