Precision finishing is skill-demanding for workers and its automation is demanded for quality control. Robot arms have wide movable area and are suitable to automate such finishing processes but there is not a practical finishing robot system to be applied to various precision finishing processes such as deburring, chamfering, brushing and polishing. In order to develop such practical robot system, we focus into four technical issues: process control of soft and abrasive tools by position/force hybrid control, robot path creation, measurement of the workpiece by touch sensing, and integration of these functions. Solving these issues by integrating practical technologies enabled us to achieve almost the same quality as finished by skilled workers and the system is applied to an actual finishing process of aero engines' parts. In this paper, the selection and improvement of technologies for the four technical issues are discussed and the performance of the system is evaluated through the experiment to compare the quality of finishing with a skilled worker.