A wiring board includes a heat dissipation plate, a heat-conductive adhesive layer, an insulating layer, a thermal via, a heat dissipation metal terminal, and electrodes. The heat-conductive adhesive layer is disposed on the heat dissipation plate. The insulating layer is disposed on the heat-conductive adhesive layer. The insulating layer is formed with an opening portion. The thermal via is disposed in the opening portion of the insulating layer. The heat dissipation metal terminal is disposed on the thermal via and electrically connected to the heat dissipation plate. The electrodes are disposed on the insulating layer. The electrodes are to be connected to an electronic component.