A crossflow, plane membrane, ultrafiltration module is presented in this paper. The experimental data obtained for different concentrations of the starch/water system after modifying the transmembrane pressure and the feed inlet velocity are given. A series resistances model was applied to the experimental data in order to obtain analytically the contributions of the fouling and gel resistances. In addition, the experimental data were correlated to a diffusion model. By considering the phenomenon of concentration-polarization, this allowed us to evaluate the concentration of the gel layer to each composition of the feed flow and the mass transfer coefficients, as well as their relation with the feed inlet velocity. The density and viscosity of various solutions of the starch/water system were determined. This enabled us to evaluate the diffusion coefficient after using the Grober and Chilton-Colburn equations.