Abstract: A method for producing a conduit for a clean room application, comprising electric cables and an elongate flexible sheath which can be moved back and forth so as to form a deflecting bend between two towers, wherein the flexible sheath has a number of parallel receiving portions, each for at least one cable, wherein each receiving portion extends in the manner of a channel in a longitudinal direction from a first end to a second end; the method comprising the steps of providing at least one cable bundle of contiguous cables and providing the flexible sheath, wherein the sheath is prefabricated and the cable bundle is introduced into a receiving portion of the prefabricated sheath, wherein the prefabricated sheath comprises at least one sleeve unit having two interacting closure profiles of a closure in order to close an open state in a dust-tight manner and the cable bundle is inserted into the opened sheath transversely to the longitudinal direction or the prefabricated sheath comprises at least one sleeve u