An illuminated keyboard includes keys; a base plate; an LED circuit board on the base plate and comprising a first circuitry and LEDs; a spacer plate on the LED circuit board and comprising units each corresponding to the key, each unit including two first groove connectors, two second groove connectors, and at least one opening each for receiving the LED; an optically transmissive film circuit board on the spacer plate and comprising a second circuitry, switch contacts, and holes, the first or second groove connector passing through the hole; and a rubber plate on the film circuit board and comprising resilient domes each disposed between the key and the switch contact, the dome having a recessed top for retaining the key, a bottom stem, and through holes grouped as groups each around the dome. The first or second groove connectors are adapted to pass through the holes.