This study has been focused on application of ELID mirror-surface grinding technology for manufacturing single crystal optic sapphire. Single crystal sapphire is a superior material with optic properties of high performance as light transmission, thermal conductivity, hardness and so on. Mirror-surface machining technology is necessary to use sapphire as optic parts. The ELID grinding system has been set up for machining of the sapphire material. According to the ELID experimental results, it shows that the surface of sapphire can be eliminated by metal bonded wheel with micron abrasives and the surface roughness of 60nmRa can be gotten using grinding wheel of 2,000 mesh in 4.5um, depth of cut. In this study, the chemical experiments after ELID grinding also has been conducted to check chemical reaction between workpiece and grinding wheel on ELID grinding process. It shows that the chemical reaction has not happened as the results of the chemical experiments.