The first gate insulating film is an insulating film made of silicon oxide, and to which hafnium (Hf) is added without addition of aluminum (Al). Also, the second gate insulating film is an insulating film made of silicon oxide, and to which aluminum is added without addition of hafnium. The third gate insulating film is an insulating film made of silicon oxide, and to which aluminum is added. Further, the fourth gate insulating film is an insulating film made of silicon oxide, and to which hafnium is added. Accordingly, it is possible to reduce the power consumption of the semiconductor device.