A keyboard includes a first substrate, a second substrate, a first electrode layer, and a second electrode layer. The first substrate includes a first upper surface and a first lower surface opposite the first upper surface. The second substrate is positioned apart from the first substrate and includes a second upper surface and a second lower surface. The second upper surface faces the first lower surface. The first electrode layer is positioned on the first lower surface and includes a number of first conductive layers disposed apart from each other and including a carbon nanotube layer structure. The second electrode layer is positioned on the second upper surface and includes a second conductive layer. A number of keys is positioned on the first upper surface or the second lower surface.