A semiconductor device includes first and second wells formed side by side as impurity diffusion regions of a first conductive type in a semiconductor substrate, below an intermediate dielectric film that covers a major surface of the substrate. A conductive layer formed above the intermediate dielectric film is held at a potential. A first resistive layer is formed on the intermediate dielectric film and is electrically connected to the first well. A second resistive layer is formed on the intermediate dielectric film and is electrically connected to the second well. The first resistive layer and first well form a first resistance element. The second resistive layer and second well form a second resistance element.