A technique capable of improving reliability of a semiconductor device is provided. In the present invention, as a wiring board on which a semiconductor chip is mounted, a build-up wiring board is not used but a through wiring board THWB is used. In this manner, in the present invention, the through wiring board formed of only a core layer is used, so that it is not required to consider a difference in thermal expansion coefficient between a build-up layer and the core layer, and besides, it is not required either to consider the electrical disconnection of a fine via formed in the build-up layer because the build-up layer does not exist. As a result, according to the present invention, the reliability of the semiconductor device can be improved while a cost is reduced.