A semiconductor chip is mounted onto a wiring substrate having external connecting terminals, electrodes on the semiconductor chip and wiring lines on the wiring substrate are connected together electrically through bonding wires, and a sealing portion is formed by resin molding, to form an IC body. Further, a case formed of a thermoplastic resin is provided. The IC body is mounted into a recess of the case through a bonding material. Thereafter, a region near the recess of the case is deformed plastically to fix the IC body to the case and then the bonding material is cured. In this way there is fabricated an IC card comprising the case and the IC body whose stability is improved by being bonded to the case through the bonding material. The production yield of the IC card can be improved.