According to one embodiment, an illumination device includes an anode, a metal layer, a cathode, an organic electroluminescent unit, first and second insulating layers, and a plurality of conductive piercing layers. The metal layer has an electrical resistance lower than that of the anode. The cathode is provided between the anode and the metal layer. The organic electroluminescent unit is provided between the anode and the cathode. The first insulating layer is provided between the cathode and the metal layer. The conductive piercing layers pierce the organic electroluminescent unit, the cathode, and the first insulating layer along a direction from the anode toward the metal layer to electrically connect the anode to the metal layer, and are separate entities from the metal layer. The second insulating layer is provided between the organic electroluminescent unit and the conductive piercing layers and between the cathode and the conductive piercing layers.