According to one embodiment, a semiconductor device includes a first complementary semiconductor device provided on a semiconductor substrate, and including a CMOS circuit, a metal electrode provided above the first complementary semiconductor device, a semiconductor layer provided above the metal electrode, including an nMOS region and a pMOS region separated from each other, and containing Ge; and a second complementary semiconductor device including an nMOSFET provided on the first portion of the semiconductor layer and a pMOSFET provided on the second portion of the semiconductor layer.