A plasma cutting torch comprising: - a torch body; - an electrode mounted in the torch body; - a nozzle mounted on the proximal end of the torch body, surrounding the tip of the electrode to form a chamber where plasma is generated by feeding a first fluid into it, and having a first central through hole for the passage of the plasma; - a nozzle support or holder joined to the torch body and whose inside wall faces the outside wall of the nozzle in such a way as to form a cooling chamber through which a second, cooling fluid flows; - a first nozzle and nozzle holder covering unit joined to the torch body having a proximal end and a distal end, the proximal end of the first unit being provided with a second central hole for the passage of the plasma; - a first channel formed between the nozzle holder and the covering unit and allowing a third fluid to flow towards the second hole; - a second unit for partly covering the first unit and designed to form, together with the outside surface of the first unit facing the second unit, a second channel for the passage of a fourth fluid leading to the outside of the first unit in the direction of the second hole, thereby cooling at least the outside of the first unit itself, characterized in that the first unit comprises a first part composed of a first supporting member which, close to its distal end, can be joined to the torch body, and a second part composed of a second member which is shaped to at least partially match the profile of the nozzle and of the nozzle holder and which can be joined by its annular edge to the proximal end of the first supporting member, wherein the second unit, which is cylindrical in shape, encompasses and covers the first member and is positioned with its proximal end close to the second member in such a way as to enable said fourth fluid to flow in the direction of the second member, thereby creating a protective area around the second member to prevent molten material from adhering to the second member. - a torch body; - an electrode mounted in the torch body; - a nozzle mounted on the proximal end of the torch body, surrounding the tip of the electrode to form a chamber where plasma is generated by feeding a first fluid into it, and having a first central through hole for the passage of the plasma; - a nozzle support or holder joined to the torch body and whose inside wall faces the outside wall of the nozzle in such a way as to form a cooling chamber through which a second, cooling fluid flows; - a first nozzle and nozzle holder covering unit joined to the torch body having a proximal end and a distal end, the proximal end of the first unit being provided with a second central hole for the passage of the plasma; - a first channel formed between the nozzle holder and the covering unit and allowing a third fluid to flow towards the second hole; - a second unit for partly covering the first unit and designed to form, together with the outside surface of the first unit facing the second unit, a second channel for the passage of a fourth fluid leading to the outside of the first unit in the direction of the second hole, thereby cooling at least the outside of the first unit itself,