Abstract: The invention relates to a method for producing double or multilayer ferroelectret with defined cavities by: structuring at least one first surface of a first polymer film (1) forming a height profile, applying ate least one second polymer film (5, 1?) to the structured surface on the first polymer film formed in step a), joining the polymer films (1, 1?, 5) to give a polymer film composite with the formation of cavities (4, 4?) and electrically charging of the inner surfaces of the cavities (4, 4?) formed in step c) with opposing electrical charges. The invention further relates to ferroelectret multilayer composites, optionally produced by said method, comprising at least two polymer films, arranged one over the other and connected to each other, wherein cavities are formed between the polymer films. A piezoelectric element comprising a said ferroelectret multilayer composite is also disclosed.