[en] This paper, reviews briefly the technological difficulties encountered in designing a blanket, this component of the fusion reactor which performes two crucial tasks: to recover 80% of the energy released by the fusion reaction, and to breed tritium to replace that burned in the fusion process. The four blanket concepts presently developed in the European Community have been designed so as to meet the specifications of a fusion demonstration reactor. Two of these concepts rely on the use lithiated ceramics as breeding material of beryllium as neutron multiplier material, and of helium as coolant. They mainly differ by the cooling system: pressure tubes for one externally-cooled breeder rods for the other. The two other concepts use Li₁₇Pb₈₃. One is water-cooled, the other self-cooled