an n-channel MIS transistor which is fabricated on a substrate and which includes a p-type semiconductor region formed on the substrate, a first gate insulating film formed on the p-type semiconductor region, a first lower layer gate electrode which is formed on the first gate insulating film and whose film thickness is one monolayer or more and 3 nm or less, and a first upper layer gate electrode which is formed on the first lower layer gate electrode, which is made of metal material, and whose average electronegativity is 0.1 or more smaller than the average electronegativity of the first lower layer gate electrode; and

a p-channel MIS transistor which is fabricated on the substrate and which includes an n-type semiconductor region formed on the substrate, a second gate insulating film formed on the n-type semiconductor region, and a second gate electrode which is formed on the second gate insulating film and is made of the metal material.