Transport properties of a new type of filtering material, prepared by tangential filtration of a protein solution on a macroporous ceramic support, were determined. Retention characteristics were studied by filtration of polyethylene glycol solutions with various molecular weights at different pH and ionic strengths. The pore radii (1.5 mn) were estimated from pure water hydraulic permeability and reflection coefficients through the use of a theoretical model based on the Verniory pore theory. The protein layer morphology was examined by scanning electron and atomic force microscopy.