Cooling system of heat-producing elements, more particularly semiconductors of electronic components contained in drawers of metal cabinets or racks placed in a room, comprising a first phase transition fluid, intended to cool said heat-producing elements housed in at least one of said drawers in order to remove the heat generated by said drawer so as to maintain it at a preset temperature, said first fluid circulating in a first fluid circuit a secondary cooling fluid, identical to said first fluid, intended to transfer directly to the outside the heat transmitted by said first fluid, said secondary cooling fluid circulating in a second fluid circuit which includes a heat sink placed outside of the room said first and second fluid circuits being in fluid communication one with the other so as to form a heat pipe connected to said heat sink placed outdoors, said system being characterised in that in each drawer of each rack a plurality of heat pipes being placed in contact with said electronic elements, the ends of each of said heat pipes being tightly connected, respectively, to a small hot collector in which vapour lines of said heat pipes converge, and to a small cold collector wherein liquid lines of said heat pipes converge, each small cold collector and each small hot collector of each drawer being inside said drawer and connected with removable connection means to, respectively, a larger cold collector and a larger hot collector, said larger collectors (230, 240) being placed outside on the back of the rack and connected hydraulically to said sink, said larger collectors (230, 240) and heat pipes of said electronic elements forming a continuous circuit of the loop "heat pipe" type. a first phase transition fluid, intended to cool said heat-producing elements housed in at least one of said drawers in order to remove the heat generated by said drawer so as to maintain it at a preset temperature, said first fluid circulating in a first fluid circuit a secondary cooling fluid, identical to said first fluid, intended to transfer directly to the outside the heat transmitted by said first fluid, said secondary cooling fluid circulating in a second fluid circuit which includes a heat sink placed outside of the room said first and second fluid circuits being in fluid communication one with the other so as to form a heat pipe connected to said heat sink placed outdoors, said system being characterised in that in each drawer of each rack a plurality of heat pipes being placed in contact with said electronic elements, the ends of each of said heat pipes being tightly connected, respectively, to a small hot collector in which vapour lines of said heat pipes converge, and to a small cold collector wherein liquid lines of said heat pipes converge, each small cold collector and each small hot collector of each drawer being inside said drawer and connected with removable connection means to, respectively, a larger cold collector and a larger hot collector, said larger collectors (230, 240) being placed outside on the back of the rack and connected hydraulically to said sink, said larger collectors (230, 240) and heat pipes of said electronic elements forming a continuous circuit of the loop "heat pipe" type.