The present invention relates to an asymmetric polymer film, in particular based on polazoles, a method for the production of the same and its use. The polyazole-based asymmetric polymer film according to the invention has a smooth and a rough side and enables, on account of its asymmetric structure, rapid and homogeneous doping with acids to form a proton-conducting membrane. The polyazole-based asymmetric polymer film according to the invention can be used in diverse ways on account of its excellent chemical, thermal and mechanical properties and is particularly suitable for the production of polymer electrolyte membranes (PEM) for so-called PEM fuel cells.