A display device is provided. The display device includes a substrate, and a light-emitting unit disposed on the substrate. The light-emitting unit includes a first conductive layer overlapping a second conductive layer, a first semiconductor layer disposed between the first conductive layer and the second conductive layer, a second semiconductor layer disposed between the first semiconductor layer and the first conductive layer, a quantum well structure disposed between the first semiconductor layer and the second semiconductor layer, and a via hole penetrated through the first semiconductor layer and the quantum well structure. The second conductive layer is electrically connected with the second semiconductor layer through a conductive material disposed in the via hole.