A printed-board includes a first conductor-layer, a second conductor-layer provided to a layer different from the first conductor-layer, an insulation-layer provided between the first conductor-layer and the second conductor-layer, a plurality of through-holes that pass through the first conductor-layer, the second conductor-layer, and the insulation-layer, and a plurality of vias that are formed in the plurality of through-holes, respectively, and couple the first conductor-layer and the second conductor-layer, each of the plurality of vias including a conductor portion that occupies part of an internal space of the through-hole, and a non-conductor portion that occupies remaining part of the internal space, wherein in a given pair of vias adjacent to each other, the conductor portion of one of the pair of vias is arranged so as to face the non-conductor portion of another one of the pair of vias.