With the objective of enabling a reduction in the size of a final semiconductor device and its thinning, and attaining facilitation of a manufacturing process, the semiconductor device includes a circuit chip having a flat mounted surface, a circuit chip smaller in size than the former circuit chip, and a sheet-like support. The latter circuit chip is formed over a substrate and has a flat back surface fixed to the substrate and a flat surface positioned on the side opposite to the back surface. The support is bonded to the surface of the latter circuit chip and supports the latter circuit chip. Then, the back surface of the latter circuit chip supported by the support is peeled from the substrate and pressed against the mounted surface, thereby fixing the back surface of the latter circuit chip and the mounted surface by an intermolecular bonding force (e.g., hydrogen bonding).