A semiconductor device includes a first MIS transistor and a second MIS transistor. The first MIS transistor includes a first gate insulating film which is formed on a first active region of a semiconductor substrate and has a first high dielectric constant film, and a first gate electrode formed on the first gate insulating film. The second MIS transistor includes a second gate insulating film which is formed on a second active region of the semiconductor substrate and has a second high dielectric constant film, and a second gate electrode formed on the second gate insulating film. The second high dielectric constant film contains first adjusting metal. The first high dielectric constant film has a higher nitrogen concentration than the second high dielectric constant film, and does not contain the first adjusting metal.