After the formation of a first interlayer insulating, an etching stopper film made of SiON is formed thereon. Subsequently, a contact hole extending from the upper surface of the etching stopper film and reaching a high concentration impurity region is formed, and a first plug is formed by filling W into the contact hole. Next, a ferroelectric capacitor, a second interlayer insulating film, and the like are formed. Thereafter, a contact hole extending from the upper surface of the interlayer insulating film and reaching the first plug is formed. Then, the contact hole is filled with W to form a second plug. With this, even when misalignment occurs, the interlayer insulating film is prevented from being etched.