The invention essentially concerns a method for regenerating a device for filtering exhaust gases produced by an engine, said method being of the type whereby the particles, retained on a filtering means of said filtering device, are burnt by the action of a combustion catalyst. Said method is characterized in that it essentially consists in using an ammonium nitrate solution, so as to produce an intimate mixture between the nitrate and the carbon particles and cause said particles to be burnt. The invention also concerns a device for implementing said method, which mainly comprises means for filtering (22) exhaust gases contained in a reaction chamber (18), in the path of the exhaust gas streams produced by an engine (10) and means for injecting the ammonium nitrate solution connected to said reaction chamber (18).