a manufacturing method of a semiconductor device incorporating a passive element includes the steps as follows : a redistribution board forming step forms a redistribution board incorporating the passive element on a base board ; a semiconductor element mounting step mounts at least one semiconductor element formed on an opposite side surface of the redistribution board with regard to the base board ; a base board separating step separates the base board from the redistribution board and exposes the other surface of the redistribution board ; a redistribution board mounting step mounts the redistribution board on a package board via electrode pads exposed from the other surface of the redistribution board .