Abstract: A porous fluorocarbon membrane has a porous support completely impregnated with tetrafluoroethylene/vinylidene fluoride copolymer. There is a process for producing this membrane by impregnating a porous support with a copolymer solution in a readily-boiling solvent and a precipitating mixture of alcohol and water followed by curing for partial hardening of the solution and subsequent drying at elevated temperature. A cartridge filter includes protective and supporting cylindrical perforated hollow housings, containing a fluorocarbon membrane or two superimposed flourocarbon membranes. Membranes and a cartridge filter find extensive use in separation of gases and aggressive media.