Abstract :� � This research presents an applied machine audits run test by applying the principle of laser interferometer. By describing how to install a laser measuring device, applied machine that developed. Proposed measure system consists of installing a reflector mirror. This paper has 2 experiments; the first experiment, finding the correction and uncertainty of the applied machine, secondly, measuring the surface roughness of the test piece. The uncertainty of this system is determined from the laser interferometer, an application tool and environment.