Facilitated transport of SO2 through supported liquid membranes containing water as a carrier was studied experimentally and theoretically in the range of SO2 partial pressure, p(F,SO2),from 3.5 Pa to 2 kPa. The permeance of SO2 at P-F,P-SO2 = 3.5 Pa was as high as 6 x 10(-4) mol m(-2) s(-1) kPa(-1), and the contribution of gas-phase mass transfer resistance to the overall mass transfer resistance was found to be significant. The observed SO2 permeance was analyzed on the basis of the theory of facilitated transport which had been developed by the present authors for the facilitated transport of CO2 using amine as a carrier. The theory could quantitatively explain the effect of various experimental conditions such as the SO2 partial pressure and the membrane thickness on the permeance of SO2 Comparison of the present facilitated transport membrane with polymeric membranes showed that the present membrane is much more effective for the removal of SO2 at low partial pressures encountered in flue gas desulfurization processes.