In a printed circuit board of the invention, a first signal wiring layer, a first ground layer, a second ground layer and a second signal wiring layer are laminated via an insulating material. A first signal wiring is formed on the first signal wiring layer and a second signal wiring is formed on the second signal wiring layer. The two signal wirings are connected via a first through hole. The conductive first ground layer and the conductive second ground layer are connected via a second through hole. The second through hole is insulated from the first through hole and formed so as to surround the first through hole.