Abstract: The invention relates to a nontransferred arc plasma torch comprising: a tubular torch body (10); at least one cathode (20) placed inside said torch body and defining a so-called cathode cavity (50); and at least one tubular anode (30) also placed inside the torch body and forming a plasma ejection nozzle. Said torch is characterized in that the torch also comprises a means (100) for minimizing the resonant pressure waves in said or each cathode cavity. The invention also relates to a method for stabilizing a plasma torch by means of acoustic coupling of the cathode cavity thereof to at least one acoustic oscillator. The invention moreover relates to the use of a thus-stabilized torch for surface coating deposition.