In recent years, the automation of polishing and finishing technologies has become a requirement because polishing and finishing with high accuracy takes a long time and often depends on the experience and special skills of technical engineers. One of the most promising polishing technologies is Field-assisted Fine Finishing (FFF), which has attracted a lot of attention from many researchers. In FFF, an electric field or a magnetic field is applied for finishing, polishing, and so on. In this study, a new polishing technology using Electro-rheological Gel (ERG) is proposed. The ERG we have developed is a functional material whose induced shear force changes according to the applied electric field intensity. A thin ERG sheet with abrasive grains is applied to the polishing pad of a rotary polisher. The properties of the ERG polishing pad can be changed by adjusting the intensity of the electric field applied to the ERG pad. We conducted experiments to analyze the basic performance of the ERG polishing method. The results show that the polishing efficiency can be improved by applying an electric field.