A keyboard includes a housing having a number of cavities to slidably receive shanks of a number of key pads, and a light device for lighting the key pads. The lighting device includes a number of light members engaged in the shanks of the key pads, the housing includes two conductive projections extended into each of the cavities to selectively engage with terminals of the light members, and to energize the light members when the key pads are depressed by the users. A spring biasing device may bias the key pad to disengage the terminals of the light members from the conductive projections.