Fuel cell and method for making such a cell with large active surface and reduced volume

The present invention relates to a process for producing a fuel cell, comprising a step of forming a plurality of holes ( 10 ) in at least two substrates ( 9 ); each hole is in the seat of an individual fuel cell, the said holes having a particular geometry, such as a shape of a truncated cone or a truncated pyramid shape. The various individual cells are then electrically connected by networks of electrical connections ( 11, 12 ) and are supplied via a reactant distribution network, the assembly formed by a substrate ( 9 ), the cells and the networks constituting a base module ( 9 '). Finally, at least two base modules ( 9 ') are assembled, the individual cells of each base module being positioned facing the individual cells of the adjacent base module(s).