NOVELTY - Bipolar plate for a fuel cell comprises a framework of two thin plates (30) spaced apart by segments (32, 34, 35) between which circulates a cooling agent. Fuel and oxidant collectors supply, via feed channels (33), circulating channels (21I, 21S) formed by water jets in feed plates (20I, 20S) made of composite conductive material.    USE - For electric vehicles, particularly buses, trams and trolley-buses, and for stand-by electricity supply in hospitals and other establishments during a disruption in mains power supply.    ADVANTAGE - Production costs of the fuel cell are reduced since prolonged and expensive machining operations are limited, thereby simplifying the manufacturing process. The structure of the bipolar plate is particularly light, since it includes phenolic resin loaded with graphite.    DETAILED DESCRIPTION - Bipolar plates consisting of a first polar plate of a basic element of a fuel cell and a second polar plate of a second basic element of a fuel adjacent to the first polar plate of the same fuel cell comprises:    (a) A flat central framework consisting of two thin parallel plates (30) spaced apart and fixed to each other by segments (32, 34, 35), and defining a first space for the passage of cooling agent;    (b) Two feed plates (20I, 20S) made of a conductive composite material and located on both sides of the flat central framework, except on the edge, and on each of which is formed at least one channel (21I, 21S) for fuel or oxidant circulation; and    (c) A frame (11) of dielectric material located on both sides of the flat central framework and around the feed plates (20I, 20S).    Collector openings (15, 16) are provided on the periphery of the flat central frame (11), to constitute fuel and oxidant collectors.    Feed channels (33) are located between the thin parallel plates (30) and connect the collector openings (15, 16) to the circulation channels (20I, 20S).    The framework includes perforated segments (35) located around the collector openings (16) and positioned between the two thin plates (30), to contribute to the continuity of the fuel and oxidant collectors.    The form of the bipolar plate is square, and at least one circulation channel (21I, 21S) of each surface of the feed plates (20I, 20S) is square spiral.    An INDEPENDENT CLAIM is given for the manufacture of a bipolar plate.    DESCRIPTION OF DRAWING(S) - The drawing shows a corner view of the bipolar plate according to the invention.    Bipolar plate (1)    Silicone inserts (4, 5)    Frame (11)    Collector openings (15, 16)    Feed plates (20I, 20S)    Circulation channels (21I, 21S)    Thin plates (30)    Segments (32, 34, 35)    Feed channels (33)