Abstract: Provided is a method of manufacturing a semiconductor package including a through wiring having precision and a low process defect. The method of manufacturing the semiconductor package includes preparing a conductive member; forming a plane part and projection parts projected from the plane part by removing portions of the conductive member; arranging the conductive member and a semiconductor chip, and forming a sealing member sealing the semiconductor chip and the conductive member; forming through wirings by exposing the projection parts of the conductive member from the sealing member; forming a re-wiring pattern layer which electrically connects the through wirings and the semiconductor chip; and forming external connection members which are electrically connected to the re-wiring pattern layer.