A novel mirror finishing method using a conductive polymer as the tool electrode is presented. It has been known that the conductive polymers have many advantages, such as to conduct a micro-current, to be easily processed into various shapes, to hold abrasives, and to have an excellent wear resistance. The effects of particle size, machining time, concentration of electrolyte, working current, and load on the surface roughness and the removal depth of SUS-304 stainless steel are investigated.When the operative parameters are set for the particle size of 3 £gm, the concentration of electrolyte of 10 wt%, the working current ranged from 10 to 20 mA, and the load of 10 N, the surface roughness Rmax, which originally is 1.4 £gm, can be reduced to 0.17~0.24 £gm after the machining time of 3 min. The surface roughness Ra can be achieved to 7.897 nm under the optimal condition. In addition, experimental results show that there is an optimal region of the working current at the concentration of electrolyte of 10 wt%. According to the surface profiles and SEM micrographs, three machining regions can be classified as (1) the mechanical polishing region, (2) the electro-chemical buffing (ECB) region, and (3) the excessive corrosion region. To achieve a high-quality mirror-like surface, the machining region must be operated at the ECB region.