Stagnation point flow in a diffusion cell was examined to determine how close the resulting flow approached that produced under ideal conditions, and to evaluate its application to mass transfer systems. Ideal conditions exist when the substance can flow directly into a barrier, then reflect cleanly without the distortion of surrounding walls. Numerical simulation was performed using a upwind difference method by directing the incoming flow through a tube perpendicular to the stagnation point, and diffusing the outgoing flow between two circular plates. Changes in the flow pattern were examined when varying the ratio of the gap between the two plates with the fixed radius of the inlet tube. All flow showed deviations from the ideal stagnation point flow. However, in the area near the stagnation point, a flow approximating the ideal was obtained by using a very small gap between the plates. An examination of the mass transfer near the stagnation point for three different gap sizes ( d = 2.0, 1.0 and 0.2) showed that the Sherwood number was approximately a half power of the Reynolds number. The dependence of the Sherwood number on the Reynolds number increased when using a smaller gap, and the Sherwood number at Re = 500 increased by 74% when the gap was decreased from d = 2.0 to d = 0.2.