A wiring board with a built-in electronic component includes a substrate having a cavity, an interlayer insulating layer formed on the substrate such that the interlayer insulating layer is covering the cavity of the substrate, a conductor layer formed on the interlayer insulating layer, an electronic component accommodated in the cavity of the substrate and including a rectangular cuboid body and three terminal electrodes such that each of the three terminal electrodes has a metal film form formed on an outer surface of the rectangular cuboid body, and via conductors formed in the interlayer insulating layer such that the via conductors are connecting the conductor layer and the three terminal electrodes of the electronic component. The three terminal electrodes are arrayed in parallel on the outer surface of the rectangular cuboid body such that adjacent terminal electrodes have the opposite polarities.