A semiconductor device may include a substrate and a through electrode. The substrate may have a first surface and a second surface opposite to the first surface, the substrate including circuit patterns formed on the first surface. The through electrode penetrates the substrate and may be electrically connected to the circuit pattern, the through electrode including a first plug that extends from the first surface in a thickness direction of the substrate and a second plug that extends from the second surface in the thickness direction of the substrate so as to be connected to the first plug.