This paper is a survey of the studies made in recent years on perfluorinated membranes, structure properties and applications. The properties and structure of these membranes were mainly studied by SAXS, SANS, NMR, ESR conductance and IR spectroscopy. Special attention has been dedicated to the solutions of these membranes and recasting of new films and composite ones. Applications in the field of fuel cells, alkali cells, electrolyzers and sensors are described.