A method of manufacturing a semiconductor package that includes: disposing a semiconductor chip on a support board; sealing the semiconductor chips with a sealant to form a sealed body on the support board, thereby forming sealed semiconductor chips; and forming a rewiring layer and bumps on a side where the semiconductor chip is disposed, after the support board is removed from the sealed body The method also includes an individualizing step of cutting the sealed body along regions corresponding to division lines on the support board, to perform individualization in such a manner that the sealed semiconductor chips each have an upper surface and a lower surface larger than the upper surface, with a side wall inclined from the upper surface toward the lower surface; and a step of forming a conductive shield layer on the upper surfaces and the side walls of the plurality of sealed semiconductor chips.