TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred process: In step 1c) and step 2c), the residual amount of solvent is such to obtain a non consolidated system. This means that the system, placed in water/ethanol (60/40 wt.%) at 50degreesC for 22 hours, dissolves almost completely. The residual amount of solvent is up to 5 wt.% with respect to the starting solvent weight. The solvent removal is carried out by thermal treatment at 45 - 95degreesC (preferably operating at atmospheric pressure). The amount of solvent after step 3c) is same as in steps 1c) and 2c) or in step 3c), the solvent is completely removed. The ionomers copolymers used in the process which contain units deriving from the sulphonic monomer CF2=CF-O-(CF2)2SO2F. The annealing of step 4) is carried out between 130 - 280 (preferably 140 - 180, especially 140 - 160)degreesC. The inert preferably non porous support and with smooth surface has size variation in each of the two directions of the plane xy is not greater than 2%, measured at the temperature of step 4) for 15 minutes; maintains unchanged the mechanical properties at the temperatures of step 4); allows an easy detachment of the catalyst coated membrane (CCM). In step 1b) and step 2b), the first electrocatalytic layer is deposited on a support containing an impression corresponding to the form of the electrocatalytic layer, removing the excess of the dispersion obtained in step 1a); the height of the first electrolytic layer, after solvent evaporation is equal to the height of the impression. The first electrocatalytic layer is obtained by placing inert support on a thin and flat sheet (where a window having the perimeter of a regular flat figure is cut out corresponding to the form of the electrocatalytic layer); deposit of the dispersion prepared in step 1a) in the window of the thin sheet; removing the excess of the dispersion by a blade running in contact with the surface of the sheet; removing solvent; removing the sheet. The second electrocatalytic layer is obtained by placing the sheet on the uncoated surface of the membrane is used where the window cut out from sheet has such shape and sizes and is positioned on the membrane so that the orthogonal projection of its perimeter on the first electrocatalytic layer is distant from the perimeter of the latter at least 1 (preferably 2) mm millimeters in each point of the projection. After step 3c), second electrolytic layer passes to step 4) by using a thermal gradient of about 10degreesC in the time of 3 - 30 (preferably 10 - 20 minutes), preferably 1degreesC/minute. The dispersion, besides the ionomer and the catalyst, contains other components as (per)fluoropolymer fillers, inorganic fillers, surfactants. The process can be optionally used other organic solvents which are miscible with water and/or with 1-3C alcohols.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrocatalytic layer comprises an ionomer and a catalyst selected between platinum or a mixture of platinum with at least one metal such as ruthenium, rhodium or molybdenum, preferably supported on carbon). The ratio by weight between catalyst and ionomer in each of the two electrocatalytic layers is 0.5 - 4 (preferably from 0.5 - 2.5). The ratio mg of catalyst metal/cm2 of electrocatalytic layer is 0.01 - 2. The ratio of (weight in mg of catalyst metal) to (cm2 of electrolytic layer is 0.01 - 0.7 mg/cm2 when hysdrogen is used as fuel; or is 0.3 - 1 mg/cm2 at the anode side and 0.5 - 2 mg/cm2 at the cathode side when methanol is used.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The (per)fluorinated ionomers are sulphonic ionomers having an equivalent weight of 380 - 1700 (preferably 500 - 1200) g/eq. The (per)fluorinated ionomers comprises copolymers containing monomeric units deriving from at least one fluorinated monomers (a1) containing at least one ethylenic unsaturation and fluorinated monomeric units (b1) containing sulphonyl -SO2F groups; and homopolymers formed of fluorinated monomeric units (b1). The ionomer hydrolysis to convert the -SO2F groups into sulphonic groups in acid -SO3H or salified form. The fluorinated monomers (a1) are selected from vinylidene fluoride (VDF); 2-8C perfluoroolefins (preferably tetrafluoroethylene (TFE)); 2-8C chloro- and/or bromo- and/or iodo-fluoroolefins (preferably chlorotrifluoroethylene (CTFE) and bromotrifluoroethylene); -CF2=CFORf1 (per)fluoroalkylvinylethers (PAVE); -CF2=CFOX perfluoro-oxyalkylvinylethers. The fluorinated monomers (b1) are selected from -F2C=CF-O-CF2-CF2-SO2F; -F2C=CF-O-(CF2-CX1F-O)n1-(CF2)n2-SO2F; -F2C=CF-O-CF2-CF2-SO2F; -F2C=CF-Ar-SO2F. The sulphonic (per)fluorinated ionomers contain monomeric units (0.01 - 2 mol.%) deriving from a bis-olefin of formula R1R2C=CH-(CF2)m-CH=CR5R6. The (per)fluorinated ionomers comprises optionally in mixture with the monomers with -SO2F groups, monomers containing precursor groups which by hydrolysis are transformed into -COOH groups selected from the -F2C=CF-CF2-CF2-Y; -F2C=CF-O-(CF2-CX1F-O)n1-(CF2)n2-Y-; -F2C=CF-O-CF2-CF2-CF2-Y; -F2C=CF-Ar-Y. The membrane and the electrocatalytic layers contain (per)fluorinated ionomers obtainable from ionomers containing monomeric units deriving from tetrafluoroethylene (TFE); monomeric units deriving from CF2=CF-O-CF2CF2SO2F.Rf1=1-6C (per)fluoroalkyl (preferably trifluoromethyl, bromodifluoromethyl and pentafluoropropyl);X=1-12C perfluoro-oxyalkyl having at least one ether group (preferably perfluoro-2-propoxy-propyl);X1=Cl, F or CF3;n1=1 - 10;n2=2 or 3;Ar=aryl ring;m=2 - 10 (preferably 4 - 8);R1, R2, R5, R6=H or 1-5C alkyl groups;Y=precursor group of the carboxylic group selected from CN, COF, COOH, COORc, COO- Me+, CONR2cR3c;Rc=1-10C alkyl (preferably 1-3C alkyl);R2c and R3c=H or Rc;Me=alkaline metal.Preferred Solvents: The solvent used in step 1a), 2a) and 3a) is selected from 1-3C alcohol (preferably n-propanol and iso-propanol) or from mixtures of 1-3C alcohol, preferably with water. EXAMPLE - A sulfonic ionomer comprising demineralized water (11.5 l); 1,1,2,2-tetrafluoro-2-trifluorovinyloxy-ethanesulfonyl fluoride monomer (980 g); and aqueous solution (3100 g) at fluoropolyoxyalkylene (5 wt.%) having acid end group with number average molecular weight 521 potassium salified, of formula CF2ClO(CF2CF(CF3)O)n(CF2O)mCF2COOK, where n/m is 10, was prepared. A sulfonic ionomer dispersion 1 (3 wt.%) was prepared by dissolving ionomer (3.1 g) in quaternary mixture (100 g) composed of water (19.5 g), isopropanol (40 g), n-propanol (40 g) and fluoropolyoxyalkylene (0.5 g) of formula CF2H-O(CF2CF2O)m(CF2O)n-CF2H with boiling 80 - 120degreesC and number average molecular weight of 350. A sulfonic ionomer dispersion 2 (8.6 wt.%) was prepared by dissolving ionomer (18.8 g) in quaternary mixture (200 g) composed of water (39 g), isopropanol (80 g), n-propanol (80 g) and fluoropolyoxyalkylene (1 g) of formula CF2H-O(CF2CF2O)m(CF2O)n-CF2H with boiling 80 - 120degreesC and number average molecular weight of 350. To a non porous polytetrafluoroethylene support, Kapton mask (RTM: polyimide) was applied having a thickness of 50 microns and in the middle a square blank space of 10 cm2. A strip of the ionomer dispersion 1 was deposited on the mask to form the electrocatalytic layer. The ionomer dispersion 1 was spread on the whole surface of the blank space of the mask, so as to fill it. It was transferred into an oven at 65degreesC for 30 minutes to evaporate the solvent. At the end it was extracted from the oven and the mask is removed obtaining on the support the first electrocatalytic layer in correspondence of the blank space of the mask. The ionomeric membrane of the catalyst coated membrane was prepared by depositing on the support, parallelly to a side of the first electrocatalytic layer, a strip of the ionomer dispersion 2. The deposition was carried out so that the strip results nearly equally protruding with respect to the edges of the considered side of the electrocatalytic layer. The dispersion was spread so as to coat the first electrocatalytic layer. It was dried in a stove at 65degreesC for 30 minutes evaporating the solvent. Thus the ionomeric membrane was formed over the first electrocatalytic layer. On the free surface of the obtained ionomeric membrane, Kapton mask (RTM: polyimide) with a thickness of 50 microns were placed. The mask was positioned so that the blank space was centered with respect to the first electrocatalytic layer. The mask was taken off and it was transferred into the oven at 65degreesC for 30 minutes to evaporate the solvent. Then the temperature was gradually increased (10degreesC/10 minutes) up to 150degreesC (annealing temperature) to obtain the second electrocatalytic layer on the free surface of the ionomeric membrane, and thus the raw coated catalyst membrane, which was supported on the polytetrafluoroethylene support at 150degreesC was for 90 minutes so as to carry out the annealing phase and then it was taken out from the oven and the polytetrafluoroethylene support was removed to obtain catalyst coated membrane. The catalyst coated membrane obtained was subjected to determine the size variations in the two orthogonal directions xy of the plane and found to be same and equal to 8% for each direction of the plane.