A wiring board with a built-in electronic component includes a substrate having cavity, an insulating layer formed on the substrate such that the insulating layer is covering the cavity, a conductor layer formed on the insulating layer, and an electronic component accommodated in the cavity and including a rectangular cuboid body and terminal electrodes such that each electrode has a metal film form formed on outer surface of the body, and via conductors formed in the insulating layer such that the via conductors are connecting the conductor layer and electrodes. The electrodes are arrayed in a matrix having rows and columns such that adjacent electrodes in row and column directions have the opposite polarities, and the conductor layer includes a line pattern shunting first group of the electrodes in one polarity and a solid pattern shunting second group of the electrodes in the other polarity.