In these days, ultra precision, high complexity and high efficiency of fine-fabrication using cutting tool are required. Not only performance of machine tool but also downsizing of high accurate working tool itself has been an important issue to realize the requirements. In this study, on-machine tool measurement technology using laser diffraction which is able to manage micro tool and able to post in the machine tool has been establishing. In this article, the on-machine tool measurement device applying dual wavelength is developed. We use the developed tool measurement device, installable size for machining center, to evaluate fundamental measurement performance.