In this paper, the mirror surface grinding of ceramics, such as Si3N4 and Al2O3-TiC, was realized with average roughness less than 10 nanometers. For the grinding operation, a three-axis CNC grinding machine tool was designed and manufactured. The grinding machine is composed of an air spindle, a high damping resin concrete bed and a three-axis CNC controller with high resolution AC servo motors. The dynamic properties of the grinding machine, such as the natural frequencies and damping of the spindle, were experimentally measured to improve the ground surface quality. Also, the truing method to improve the straightness of the grinding wheel with 1 mu m accuracy, was developed. (C) 1997 Elsevier Science Ltd.