Provided is a stacked semiconductor package, which has various kinds of semiconductor chips with various sizes and is capable of miniaturization. The stacked semiconductor package includes a base substrate layer and a sub semiconductor package disposed on a top surface of the base substrate layer. The sub semiconductor package includes a plurality of sub semiconductor chips spaced apart from one another, and a sub mold layer filling spaces between the plurality of sub semiconductor chips to surround side surfaces of the plurality of sub semiconductor chips. The stacked semiconductor package includes at least one main semiconductor chip stacked on the sub semiconductor package, the at least one main semiconductor chip being electrically connected to the base substrate layer through first electrical connection members.