This study discusses a method for increasing the efficiency and speed with which an improvement in surface roughness of a hole-wall surface can be achieved. The surface after traditional machining is discussed as well as a method for finishing the hole-wall surface using a design of finish-tool that includes a nonconductive knothole-form burnishing-tool and a ring electrode to execute simultaneous burnishing and electrofinishing (SBEF). By the dual and synchronous effect of the electrode and the burnishing-tool a superior hole-wall finish is achieved. In the experiment, the use of a small arc rounding radius and a thin finish-tool is advantageous to the finishing effect. A high rotational speed of the finish-tool produces a better finish. A high current and a faster finishing tool feed is also effective in gaining a rapid improvement of the roughness of the hole-wall surface and is recommended from the results of the current study.