A Semiconductor device includes a semiconductor substrate, an insulating film, a first conductive film, a ferroelectric film, an insulating layer, a first plug and a second plug. The semiconductor substrate includes a source region and a drain region which are formed on a main surface thereof. The insulating film is formed on the semiconductor substrate such that the insulating film is located between the source region and the drain region in a plan view. The first conductive film is formed on the insulating film. The ferroelectric film is formed on the first conductive film. The insulating layer covers the first conductive film and the ferroelectric film. The first plug reaches the first conductive film. The second plug reaches the ferroelectric film. A material of the ferroelectric film includes hafnium and oxygen. In plan view, a size of the ferroelectric film is smaller than a size of the insulating film.