A wiring board includes a core substrate including an insulation base member; linear conductors configured to pierce from a first surface of the insulation base member to a second surface of the insulation base member; a ground wiring group including a first ground wiring formed on the first surface of the core substrate, and a belt-shaped second ground wiring formed on the second surface of the core substrate and electrically connected to the first ground wiring by way of a part of the linear conductors; and an electric power supply wiring group including a first electric power supply wiring formed on the first surface, and a second electric power supply wiring formed on the second surface and electrically connected to the first electric power supply wiring by way of a part of the plural linear conductors.