A semiconductor device includes a semiconductor substrate; a well of a first conductivity type in the semiconductor substrate; a first element; and a first vertical transistor. The first element supplies potential to the well, the first element being in the well. The first element may include, but is not limited to, a first pillar body of the first conductivity type. The first pillar body has an upper portion that includes a first diffusion layer of the first conductivity type. The first diffusion layer is greater in impurity concentration than the well. The first vertical transistor is in the well. The first vertical transistor may include a second pillar body of the first conductivity type. The second pillar body has an upper portion that includes a second diffusion layer of a second conductivity type.