It is described a method of electrical by-passing of an elementary electrochemical cell, for instance a fuel cell, inserted in a filter-press structure delimited by electrically conducting bipolar sheets and provided with perimetral sealing gaskets, comprising short-circuiting the cell by insertion of a conductive material within recesses realised by perforation of materials interposed between the bipolar sheets. The gaskets and the bipolar sheets may be provided with sites predisposed to the perforation, for instance notches for a drilling tip, or gasket regions of decreased hardness.