Processing of cement raw materials has an important role in determining the characteristics and quality of production. One of the most important raw material processing process is raw mill which is used for cement raw material refinement into fine powder for easy processing later. This process produce waste in the form of gas containing dust particles. The dust must be filtered before being thrown into the air. One of the efforts in the process of dust capture is to use electrostatic precipitator (EP). The performance of this EP system is very good at reducing emissions. The efficiency of an EP design to capture dust reaches 99.9946%. The purpose of this research is to analyze the performance of EP based on the DC voltage used in the effort to decrease the emission to reduce the loss of the company. Based on the analysis that the required voltage in the emission curve is inversely proportional, the greater the voltage the EP uses in the 83 kV range, the less emissions being released into the air. Emission generated 60.77 mg / s. Then the efficiency of the actual calculation results reached 99.99%.