A semiconductor device according to an embodiment includes: a semiconductor substrate; a resistance element of a first conductivity type formed in one region of the semiconductor substrate; a field effect transistor of a second conductivity type formed in another region of the semiconductor substrate; and a field effect transistor of the first conductivity type formed in still another region of the semiconductor substrate. The resistance element includes: an insulating film formed in an upper layer portion of the semiconductor substrate; and a well of the first conductivity type formed immediately below the insulating film, an impurity concentration at an arbitrary depth position in the well of the first conductivity is lower than an impurity concentration at the same depth position in a channel region of the field effect transistor of the second conductivity type.