The present invention relates to a process for producing a dielectric polyurethane film, in which at least the following steps are performed continuously: I) a mixture comprising: a) a compound containing isocyanate groups and having a content of isocyanate groups of >10% by weight and ≦50% by weight, b) a compound containing isocyanate-reactive groups and having an OH number of ≧20 and ≦150, at least one solvent having a vapor pressure at 20° C. of >0.1 mbar and