Tetrachloroethene (PCE) is one of the grave environmental pollutants. Certain anaerobic bacteria have the ability to dechlorinate PCE as an electron acceptor for their respiration (dehalorespiration). Previously, we accumulated PCE-dechlorinating culture in the presence of Fe(III)-EDTA. In this study, we have described the regulation of dehalorespiration by electrolytic control of the Fe(II)/Fe(III) ratio using a potentiostat (electrochemical cultivation). PCE-dechlorinating culture was cultivated under H2 conditions at constant redox potentials ranging from –0.1 to –0.8 V. After electrochemical cultivation for 3 weeks, PCE-dechlorinating activity of the mixed culture varied at different redox potentials. At –0.6 V, the culture showed the highest activity and the highest ratio of Desulfitobacterium/total bacteria. Electrochemical cultivation is a useful method for regulating PCE-dechlorinating bacterium.