The use of a new renewable energy was an impulse because the impact of the fossil energy that damages the environment and eventually will run out of its limitation. Biogas was a new renewable energy that was environtally friendly. The contents of Biogas were CH4, CO2, N2, H2, H2S and O2. The highest content of Biogas was CH4 (55%-75%), beside it was also a pollutant content of Biogas 25%-45%. The highest the contents of CH4 in the Biogas then made the higher the heat value of Biogas. To increase the heat value of Biogas was needed a filter of the pollutant content. Zeolit that was activated, molten NaOH, and solid NaOH was the ingredients that can be used as Biogas Filter. The result of study showed that the use of Biogas Filter can improve the performance of Generator. The Biogas Filter was proven that can reduce the pollutant contents in the Biogas, so the performance of generator should be better. If it was compared to the use of Biogas Filter, the use of Zeofilter could increase the voltage of 3,72 %, ampere of 0,31 %, power of 5,59 %, torque of 6,41 % and rotation decreased for 1 %. The use of molten NaOH filter can increase the voltage of 5,85 %, ampere of 1,95 %, power of 9,53 %, torque of 6,73% and rotation of 2 %. The use of solid NaOH Filter could improve the voltage of 14,89 %, ampere of 10,80 %, power of 33,12 %, torque of 14,19 % and rotation of 15 %.