Gas-liquid contactors equipped with hydrophobic porous membranes were tested to measure the critical breakthrough pressure and operated for removal of sulfur dioxide. The critical breakthrough pressure through the porous membrane was measured with pure water, NaOH aqueous solution and Na2SO3 aqueous solution. The selective absorption of SO2 Occurs into the aqueous electrolyte solutions through the porous polymer membrane. As an absorbent, pure water, NaOH aqueous solution and Na2SO3 aqueous solution were supplied. The separation performance of sulfur dioxide with different membrane materials were evaluated in terms of the concentration of absorbent, the concentration of sulfur dioxide, and the feed flow rate. As the concentration of absorbent increased, the removal efficiency increased. By increasing the concentration of sulfur dioxide and the feed flow rate, the removal efficiency was observed to be decreased.