PURPOSE: To eliminate a gnard ring by selectively heating the sealing area of a semiconductor element and sealing the semiconductor element by softened sealing resin.

CONSTITUTION: A wire bonded substrate 2 before sealing is placed on a placing table 18 and is kept at the prescribed temperature with a heater 24 for the prescribed time. As a result, only the sealing range 28 of the substrate 2 is selectively heated by a heating part 20. As for the sealing range 28 of the substrate 2, which is kept in the heated condition, softened flowing sealing resin 30 is applied by the suitable quantity by a dispenser 32 which is a resin supplying means. Since the sealing range 28 of the substrate 2 is heated to the suitable temperature, the applied sealing resin 30 is heated and the flowability is maintained and accelerated. Then, the resin 30 is made to flow into the sealing range 28 suitably and sealing is performed. Thus, the production cost is reduced.