Abstract: Method for the production of membranes for artificial organs, in the form of tube foils, flat foils or hollow filaments, into which metals and/or metal compounds are incorporated, in which a metal salt solution is introduced into a membrane composed of a polymer, the membrane is then attacked with gaseous precipitation agent and brought to reaction for precipitation. The improvement is having the introduction of the metal salt solution and the attack with gas take place in a membrane-containing module for an artificial organ, by leading the metal salt solution and the gaseous precipitation agent successively through a space enclosed by the membrane, provided for the flow-through of blood.