A semiconductor apparatus includes a substrate, a buffer layer made of a monocrystal semiconductor material and formed on the substrate, a strained-Si layer formed on the buffer layer and having a lattice constant different from that of the buffer layer, a monocrystal insulating film formed on the strained-Si layer and made of a material having a rare earth structure with a lattice constant different from that of Si, and an electrode formed on the insulating film.