A semiconductor device comprising a buried insulating film formed in a substrate;
a protective film formed on the buried insulating film covering corresponding diffusion
regions of a P-type MISFET and a N-type MISFET, wherein the protective film is
etch resistant to a hydrofluoric acid based solution; and a wiring layer formed
on the protective film and being electrically connecting the diffusion regions
of the P-type MISFET and the N-type MISFET.