A semiconductor device according to the present invention includes: a lower-surface oxidation preventing insulating film formed on a lower surface of a metal resistor element; an upper-surface oxidation preventing insulating film formed on an upper surface of the metal resistor element; and a side-surface oxidation preventing insulating film formed only near a side surface of the metal resistor element by performing anisotropic etching after being deposited on a whole surface of a wafer in a process separated from the lower-surface oxidation preventing insulating film and the upper-surface oxidation preventing insulating film. According to the present invention, it is possible to prevent the increase of the resistance value due to the oxidation of the metal resistor element and also to prevent the increase of the parasitic capacitance between metal wiring layers without complicating the fabrication process.