A method of manufacturing a semiconductor package includes: bonding a plurality of semiconductor chips to a plurality of mounting regions on a wiring board partitioned by crossing streets; supplying a liquid resin to a front surface side of the wiring board onto which the plurality of semiconductor chips have been bonded, to seal the plurality of semiconductor chips in a collective manner, thereby forming a sealed board; cutting the sealed board along the regions corresponding to the streets, to individualize the sealed chips in such a manner that the sealed chips each have an upper surface and a lower surface larger than the upper surface, with a side surface inclined from the upper surface toward the lower surface; and forming a conductive shield layer on the upper surfaces and the side surfaces of the plurality of sealed chips.