Abstract: Generally, heater works with crude oil or residual oil as fuel. During burning of this fuel, soot settles down the inside of heater, and the heat efficiency of heater decreases as the soot accumulates continuously. In this case, soot removal of heater is necessary, but environment is polluted as the soot or fume emits to atmosphere during soot removal. Therefore, the soot to be emitted has to be disposed and recovered in accordance with related State standards about pollutant emission. By observing the characteristics of soot (adhesive and floatable), a filter-bag type soot remover is recommended after comparison between some methods of soot removal. Requirements on site use of this method are given.