A semiconductor device includes a substrate, a first electrode provided apart from the surface of the substrate in a first direction intersecting the surface of the substrate, a second electrode extending completely through the substrate in the first direction and connected to the first electrode at one end in the first direction, a first structure covering a side surface of the second electrode, and an insulating film provided between the second electrode and the first structure. The second electrode includes first atoms, and the first structure includes second atoms. A diffusion coefficient of the second atoms in the insulating film is smaller than a diffusion coefficient of the first atoms in the insulating film.