A high-pressure atomiser nozzle, comprising: - an inlet which can be fluidically connected with means for supplying a high-pressure liquid ( L ); - an outlet for the spray of atomised liquid; - a fluidic connection line extending between said inlet and said outlet comprising: - at least one first duct defining an axis ( X ) fluidically connected with said inlet ; - an operating chamber arranged downstream of said at least one first duct ; - a plurality of first openings for fluidically connecting said at least one first duct and said operating chamber configured so that the liquid ( L ) flows from the first duct into the operating chamber ; wherein said at least one first duct , operating chamber and first openings are mutually configured so that the flow of the high-pressure liquid ( L ) in said operating chamber is of turbulent type; characterized in that said operating chamber comprises a single outlet opening with small section so that the high-pressure liquid ( L ) flowing out therefrom is atomised liquid, said operating chamber having a side wall which includes said first openings , the latter extending parallel or slightly inclined with respect to said axis ( X ) in order to have a slot configuration, so that the liquid flow flows into said operating chamber transversely with respect to said axis ( X ); and further characterized in that said operating chamber comprises a first substantially flat area perpendicular to said axis ( X ) which includes said single opening , the latter and said first substantially flat area defining a sharp edge , said single opening preferably comprising a lateral surface coaxial with said axis ( X ) which forms a substantially right angle with said fist substantially flat area . - an inlet which can be fluidically connected with means for supplying a high-pressure liquid ( L ); - an outlet for the spray of atomised liquid; - a fluidic connection line extending between said inlet and said outlet comprising: - at least one first duct defining an axis ( X ) fluidically connected with said inlet ; - an operating chamber arranged downstream of said at least one first duct ; - a plurality of first openings for fluidically connecting said at least one first duct and said operating chamber configured so that the liquid ( L ) flows from the first duct into the operating chamber ; - at least one first duct defining an axis ( X ) fluidically connected with said inlet ; - an operating chamber arranged downstream of said at least one first duct ; - a plurality of first openings for fluidically connecting said at least one first duct and said operating chamber configured so that the liquid ( L ) flows from the first duct into the operating chamber ; wherein said at least one first duct , operating chamber and first openings are mutually configured so that the flow of the high-pressure liquid ( L ) in said operating chamber is of turbulent type; characterized in that said operating chamber comprises a single outlet opening with small section so that the high-pressure liquid ( L ) flowing out therefrom is atomised liquid, said operating chamber having a side wall which includes said first openings , the latter extending parallel or slightly inclined with respect to said axis ( X ) in order to have a slot configuration, so that the liquid flow flows into said operating chamber transversely with respect to said axis ( X ); and further characterized in that said operating chamber comprises a first substantially flat area perpendicular to said axis ( X ) which includes said single opening , the latter and said first substantially flat area defining a sharp edge , said single opening preferably comprising a lateral surface coaxial with said axis ( X ) which forms a substantially right angle with said fist substantially flat area . <EOS>