A wiring board includes a substrate having an opening portion, electronic components positioned in the opening portion of the substrate and including first and second electronic components, and an insulation layer formed over the substrate and the first and second components. The first component has first and second electrodes having side portions on side surfaces of the first component, the second component has first and second electrodes having side portions on side surfaces of the second component, the first electrode of the first component and the first electrode of the second component are set to have substantially the same electric potential, and the first component and the second component are positioned in the opening portion of the substrate such that the side portion of the first electrode of the first component is beside the side portion of the first electrode of the second component.