A luminous keyboard includes a light guide layer, a light source, a reflecting layer, a circuit layer, a key fixing plate, mechanical keys, and microstructures. The light guide layer has a first surface, a second surface, and a light incident surface. The light source generates a light beam to the light guide layer through the light incident surface. The reflecting layer is disposed beside the first surface of the light guide layer. The circuit layer formed on the second surface of the light guide layer has multiple switches. The key fixing plate is fixed to the second surface of the light guide layer. The mechanical keys are connected to the key fixing plate, corresponding to the switches, and are pressed to trigger the corresponding switches. The microstructures disposed on the light guide layer surround the switches, and guide the light beam from the light guide layer to the mechanical keys.