Disclosed herein is a method for manufacturing a semiconductor package which uses a base member 120 in which a first metal layer 113, a barrier layer 115, and a second metal layer 117 are stacked on both surface thereof in sequence based on an adhesive member 111 to simultaneously manufacture two printed circuit boards through a single sheet process, thereby making it possible to improve manufacturing efficiency; electrically connects a semiconductor chip 300 to a printed circuit board through a solder bump 250, thereby making it possible to implement a high-density package substrate; and forms a metal post 140 instead of a through hole to required in an interlayer circuit connection, thereby making it possible to reduce costs required in the processing/plating of the through hole.