An installation element for use in cooling technology, in water treatment, or in mass transfer and a method for producing such an element. The installation element is sell supporting and is composed of a plurality of plies which are at least partially spatially structured and which are connected to each other. Adjacent plies form flow paths for a liquid and/or a gaseous medium between the adjacent plies. The installation element has at least some of the plies being composed of an at least three-layer coextruded plastic film, a center layer of the three-layer plastic film being a mechanically supporting layer, and the two outer layers are composed of a plastic having application-specific properties or are layers each having at least one additive which is added to the plastic and which gives application specific properties to the outer layers.