The mass-transfer efficiency of the parallel-plate membrane extractor module with concurrent and countercurrent flows was investigated theoretically and experimentally in this study. The analytical solution is obtained using an eigen-function expansion in terms of the power series using an orthogonal expansion technique. The theoretical predictions were represented graphically with the mass-transfer Graetz number (volumetric flow rate), flow pattern, and subchannel thickness ratio (permeable-barrier locations) as parameters, compared with those obtained by numerical approximation and experimental runs. The extractive rate, the extractive efficiency, and the mass-transfer efficiency can be achieved higher for the countercurrent-flow device than those of the concurrent-flow device by setting the barrier location moving away from the centerline. The accuracy of the experimental measurements as compared to both analytical model and approximation model were calculated by 2.11 x 10(-2) <= E <= 5.15 x 10(-2) and 4.63 x 10(-2) <= E-2 : 8.12 x 10(-2), respectively. These operating and design parameters influences on the mass-transfer efficiency enhancement are also discussed.