A display device is provided. The display device includes a substrate. A first electrode layer is disposed on the substrate. An electrochromic material single layer is disposed on the first electrode layer, wherein the electrochromic material single layer has a plurality of spherical holes inside, and wherein the electrochromic material single layer includes inorganic materials. An electrolytic layer is disposed on the electrochromic material single layer. A second electrode layer is disposed on the electrolytic layer. A power supply is electrically connected to the first and second electrode layers, respectively. The electrochromic material single layer displays red, blue or green colors according to a driving voltage provided by the power supply.