A wiring board with a built-in electronic component includes a substrate having an accommodation portion, an electronic component having an electrode and accommodated in the accommodation portion of the substrate, a conductive layer having a planar conductive pattern formed over the electrode of the electronic component, and one or more via conductors connecting the planar conductive pattern of the conductive layer and the electrode of the electronic component. The electrode of the electronic component has a portion which faces the planar conductive pattern of the conductive layer and which has a plurality of outer edges facing outward with respect to a surface of the electronic component on which the portion of the electrode is formed, and the planar conductive pattern of the conductive layer has a portion positioned directly over one or more of the outer edges of the electrode of the electronic component.