Provided is a method of manufacturing a semiconductor package. The method includes mounting a semiconductor device on a substrate; disposing a mold on the substrate, wherein the mold is formed to cover the semiconductor device such that at least one inner side surface of the mold has a slope; providing a molding material into the mold to encapsulate the semiconductor device; removing the mold from the substrate; and forming an electromagnetic shielding (EMS) layer to cover a top surface and side surfaces of the molding material.