A first film made of SiGe is formed over a support substrate whose surface layer is made of Si. A gate electrode is formed over a partial area of the first film, and source and drain regions are formed in the surface layer of the support substrate on both sides of the gate electrode. The gate electrode and source and drain regions constitute a first field effect transistor. A first stressor internally containing compressive strain or tensile strain is formed over the first film on both sides of the gate electrode of the first field effect transistor. The first stressor forms strain in a channel region.