A method of manufacturing a stacked semiconductor package using an improved technique of forming a through via in order to enable 3-dimensional vertical interconnection of stacked packages is provided. The method includes forming a seed layer required for forming a via core on a bottom surface of a wafer, forming at least one via hole vertically through the wafer, forming a via core in the via hole, insulating the via hole from the via core, and removing the seed layer from the bottom surface of the wafer. The stacked semiconductor package is suitable for high-speed signal transmission.