Abstract: When a wafer, which has completed a wafer process and has a main surface on which a plurality of bumps respectively connected to a plurality of electrode pads are formed, is brought into a resin molded type package to thereby manufacture a semiconductor device, a method of manufacturing such a semiconductor device includes placing a sheet encapsulating material containing a thermosetting resin over the wafer so as to cover the main surface of the wafer and, heating and curing the sheet encapsulating material by a heating apparatus to thereby form an encapsulating resin layer.