Abstract: A support for a laser beam generator in a carpenter's level is positioned on the level so that the laser beam generated will lie in the plane of a flat reference surface of the level. A battery or other power supply is housed in the carpenter's level together with circuitry to connect the power supply to the laser beam generator and preferably a switch allowing the generator to be turned off and on. Gauges may be employed in the level for vertical, as well as horizontal, orientation to the reference surface and, if desired, a gauge enabling the reference surface to be repeatedly placed at a predetermined angle relative to the horizontal may be included. Such a gauge may be a commercial gauge such as an inclinometer. Preferably, however, a conventional gauge employing an arcuate tube filled with liquid having a bubble in it which seeks the highest level of the tube with calibration marks for accurately positioning the bubble.