NOVELTY - Ionomeric membranes comprises (per)fluorinated, semicrystalline or amorphous, ionomeric polymers, having equivalent weight (EW) of 380-1800 g/eq, preferably 450-1650 g/eq.    USE - The invention is used for electrochemical applications such as fuel cells, electrochemical cells, or electrolyzers for hydrochloric acid.    ADVANTAGE - The invention has good mechanical properties, and improved ionic conductivity.    DETAILED DESCRIPTION - Ionomeric membranes comprises (per)fluorinated, semicrystalline or amorphous, ionomeric polymers, having EW of 380-1800 g/eq, preferably 450-1650 g/eq, which when used in fuel cell, membrane thickness 50 microns assembled between two electrodes catalyzed with 0.6 mg/cm2 platinum supported on carbon and treated with 0.7 mg/cm2 of Nafion, having 10 cm2 area; hydrogen and air feeding, both at 0.25 MPa, both saturated with water at 80degreesC, cell temperature 75degreesC, for membranes tetrafluoroethylene/F2CCFO(CF2)2SO2F, give the following maximum specific power values (Pmax) at the indicated EW values: EW= 670 Pmax higher than 0.55 Watt/cm2; EW=830 Pmax higher than 0.66 Watt/cm2; EW=1160 Pmax higher than 0.5 Watt/cm2; EW=1600 Pmax higher than 0.32 Watt/cm2. An INDEPENDENT CLAIM is also included for a method to obtain the (per)fluorinated ionomeric membranes, comprising:    (1) loading of the semicrystalline or amorphous (per)fluorinated polymer, solid or liquid, in a mold comprising a hollow cylinder (1) equipped with a thermocouple to measure the temperature on the internal surface of the cylinder, a chuck (2) having a diameter lower than that of the cylinder, equiaxial with the cylinder, equipped with thermocouple to measure the temperature on the external surface of the cylinder, two rings (3, 4) perpendicular to the axis of the cylinder closing the mold, one of the rings being sliding along the chuck to convey inside the cylinder the pressure applied on their surfaces, the mold being heated on the external surfaces;    (2) degassing the mold containing the polymer, when the loaded polymer is solid, heating up to the polymer is in the liquid form, exerting inside the mold a pressure not lower than 1 MPa, generally by operating at not greater than 50 MPa, preferably not greater than 30 MPa, when the loaded polymer is in the liquid state in the mold, the heating step is omitted and degassing is ended when the difference of the temperature between the internal surface of the cylinder and the external surface of the cylinder is lower than 10degreesC;    (3) cooling the mold until lower than 30degreesC, preferably 15-25degreesC, operating at 1-10 MPa, after solidification of the polymer, extraction from the mold of the polymer manufactured article (sleeve); and    (4) obtainment of the membrane by sleeve exfoliation, carried out by rotating the sleeve on its longitudinal axis at 1-500 rpm putting the sleeve surface into contact with a blade, parallel to the cylinder axis, to obtain a film with a constant thickness.    DESCRIPTION OF DRAWING(S) - The figure shows the mold.    Cylinder (1)    Chuck (2)    Rings (3, 4)