The Invention relates to a drawn polymer film, comprising (A) a polymer or polymer blend and at least (B) one additional component with an average particle diameter of between 0.1 and 15 μm, which by means of (C) one or several secondary treatment steps is processed to form a membrane after being drawn. The average particle diameter of component (B) ranges between 0.1 and 15 μm, preferably 0.5-8.0 μm, with the range between 1.0 and 7.0 μm being particularly preferred. The membranes are used for alkene-alkane separation, electrodialysis, the desalinization of seawater, in fuel cell applications and other membrane applications.