TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The metal components deposited in step (c) are metals, alloys of two or more metals or metal compounds selected from oxides, sulfides, carbides and nitrides, the metals specifically being alkali or transition metals, especially iron, zirconium, nickel, niobium or cobalt. Stage (c) is carried out by physical vapor deposition, specifically by ion bombardment, especially at an angle of deposition of less than 45 degrees . At least one further metallic layer is optionally deposited on the membrane formed in step (c). Preferred Product: The claimed membranes (I) have a layer containing a metals, an alloy of two or more metals or a metal compound selected from oxides, sulfides, carbides and nitrides; and preferably have at least two layers with different metaalic compositions. EXAMPLE - A template membrane was prepared by incorporating a 99.999% pure aluminum sheet (previously ultrasonically cleaned and heated under nitrogen at 400 degrees C for 3 hours) as the anode in an electrolytic cell with a platinum cathode, electrocleaning using a solution of perchloric acid and ethanol, anodizing under stirring at 40 V using an oxalic acid electrolyte, chemically treating the initial oxide film using an aqueous mixture of phosphoric and chromic acids and further anodizing under the same conditions to give an anodic oxide film with completely hexagonally symmetrically ordered nanopores (diameter ca. 60 nm) on a non-porous alumina barrier layer (itself on the aluminum substrate). The alumina membrane was deposited on a silica support (to facilitate handling) and used as substrate for growth of a metal layer by gas phase deposition, using metal vaporized by bombardment with argon ions under a high vacuum of less than 10-6 mbar. The thickness of the deposited layer was controlled by using an angle of deposition of 30 degrees . The deposited metal layer plus the alumina layer was detached from the silica substrate by immersion in ethanol-water (1:3), followed by removal of the alumina layer by immersion in 5 vol. % phosphoric acid for 1 hour at 20 degrees C. The obtained metal membrane was washed with water, dried with ethanol, dried at 70 degrees C for 2 hours and (if necessary for the particular metal) stored under nitrogen, argon or vacuum to prevent oxidation. Using this procedure, a porous zirconium membrane of thickness 100 nm was grown in 50 minutes.