A resin sealing method of a semiconductor device includes: positioning semiconductor devices at predetermined positions of an adhesive layer formed on a support body and adhering the semiconductor devices thereto, sealing a part of each of the semiconductor devices with resin by curing a first seal resin in a fluidization state so as to fix the semiconductor devices adhered to the predetermined positions of the adhesive layer formed on the support body, setting the semiconductor devices fixed to the predetermined positions of the adhesive layer formed on the support body in a mold and sealing the exposure parts of the semiconductor devices exposed from the first seal resin with a second seal resin, and removing the support body and the adhesive layer from the semiconductor devices sealed with the resin.