Abstract: Novel laminated, polyfluorocarbon microporous membranes are made up of three or more sheets of aggregated microporous fluorocarbon polymer. A fine porosity pore-containing microporous fluorocarbon polymer sheet has an average pore diameter of from about 0.01.mu.m to about 1.0.mu.m. This fine porosity sheet is laminated between a first sheet or sheets of larger porosity microporous fluorocarbon polymer and a second sheet or sheets of larger porosity microporous fluorocarbon polymer. At least one and preferably both of the first and second sheets has an average pore diameter of from about 1.0.mu.m to about 10.0.mu.m. A novel microporous polyfluorocarbon filter cartridge utilizing the membrane is also disclosed. A cartridge body formed of polyfluorocarbon has an inlet and outlet with a membrane assembly disposed in the cartridge so that fluid moving from the inlet to the outlet must pass therethrough.