A method for mineralizing a biopolymer membrane, comprising the following steps: a) Introducing an assembly consisting of a biopolymer membrane comprised between two cellulose sheets (A) and (B), into a container comprising: - a first compartment and a second compartment , each comprising an electrode, a first electrode being an anode placed in the first compartment and a second electrode being a cathode placed in the second compartment , - the walls of the first compartment and of the second compartment in contact with each other having each an opening putting into communication the first and the second compartment, the assembly being disposed in said opening between the first and the second compartment so as to close it, the cellulose sheet (A) being on the side of the first compartment and the cellulose sheet (B) on the side of the second compartment , b) filling the first compartment with an aqueous solution containing at least one cation selected from: calcium ions, silver ions, zinc ions, copper ions, sodium ions, magnesium ions and aluminum ions, and the second compartment with an aqueous solution containing at least one anion selected from fluoride ions, sulphate ions, carbonate ions, silicate ions and phosphate ions; c) applying an electric voltage between the electrodes; d) turning the assembly over so that the cellulose sheet (A) is on the side of the second compartment and the cellulose sheet (B) on the side of the first compartment, or exchanging the solutions and electrodes of the first and the second compartment; c') applying an electric voltage between the electrodes, said voltage being equal to that applied in step (c) and being applied for a duration identical to that of step (c); e) removing and rinsing the assembly ; f) recovering and drying the mineralized biopolymer membrane. a) Introducing an assembly consisting of a biopolymer membrane comprised between two cellulose sheets (A) and (B), into a container comprising: - a first compartment and a second compartment , each comprising an electrode, a first electrode being an anode placed in the first compartment and a second electrode being a cathode placed in the second compartment , - the walls of the first compartment and of the second compartment in contact with each other having each an opening putting into communication the first and the second compartment, the assembly being disposed in said opening between the first and the second compartment so as to close it, the cellulose sheet (A) being on the side of the first compartment and the cellulose sheet (B) on the side of the second compartment , - a first compartment and a second compartment , each comprising an electrode, a first electrode being an anode placed in the first compartment and a second electrode being a cathode placed in the second compartment , - the walls of the first compartment and of the second compartment in contact with each other having each an opening putting into communication the first and the second compartment, b) filling the first compartment with an aqueous solution containing at least one cation selected from: calcium ions, silver ions, zinc ions, copper ions, sodium ions, magnesium ions and aluminum ions, and the second compartment with an aqueous solution containing at least one anion selected from fluoride ions, sulphate ions, carbonate ions, silicate ions and phosphate ions; c) applying an electric voltage between the electrodes; d) turning the assembly over so that the cellulose sheet (A) is on the side of the second compartment and the cellulose sheet (B) on the side of the first compartment, or exchanging the solutions and electrodes of the first and the second compartment; c') applying an electric voltage between the electrodes, said voltage being equal to that applied in step (c) and being applied for a duration identical to that of step (c); e) removing and rinsing the assembly ; f) recovering and drying the mineralized biopolymer membrane. <EOS>