Method for treatment of an exhaust stream resulting from a combustion in a combustion engine , - a first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in said exhaust stream, with the use of a first oxidation catalyst ; - a control of a supply of a first additive into said exhaust stream , with the use of a first dosage device , arranged downstream of said first oxidation catalyst ; - catching and oxidising of soot particles in said exhaust stream , with the use of a catalytic filter arranged downstream of said first dosage device , wherein said catalytic filter consists of a particulate filter with an at least partly catalytic coating with reduction characteristics; - a first reduction of nitrogen oxides NO x in said exhaust stream , with the use of said first additive and said reduction characteristics of said catalytic filter ; - a second oxidation of one or more of nitrogen oxides NO and incompletely oxidised carbon compounds in said exhaust stream , with the use of a second oxidation catalyst , which is arranged downstream of said catalytic filter ; and - a control of supply of a second additive into said exhaust stream , with the use of a second dosage device , arranged downstream of said second oxidation catalyst ; - a second reduction of nitrogen oxides NO x in said exhaust stream , with the use of at least one of said first and said second additive in a reduction catalyst device , arranged downstream of said second dosage device ; characterised in that said supply of said first additive is controlled based on a distribution of the ratio between nitrogen dioxide and nitrogen oxides NO 2_1 /NO x_1 , upstream of said catalytic filter and upstream of said first dosage device in such a manner that nitrogen dioxide NO 2_1 is present in a filter structure for said catalytic filter , whereby nitrogen dioxide NO 2_1 present in the filter structure oxidizes soot particles in said catalytic filter ; wherein said supply of said first additive, through the use of said first dosage device , is increased to a level at which residues/precipitates/crystallisation are formed; and wherein said supply of said first additive, with the use of said first dosage device is reduced or interrupted when the residues/precipitates/crystallisation are formed, following which residues of said first additive are eliminated by heat in said exhaust stream, generated in said first oxidation catalyst . - a first oxidation of compounds comprising one or more of nitrogen, carbon and hydrogen in said exhaust stream, with the use of a first oxidation catalyst ; - a control of a supply of a first additive into said exhaust stream , with the use of a first dosage device , arranged downstream of said first oxidation catalyst ; - catching and oxidising of soot particles in said exhaust stream , with the use of a catalytic filter arranged downstream of said first dosage device , wherein said catalytic filter consists of a particulate filter with an at least partly catalytic coating with reduction characteristics; - a first reduction of nitrogen oxides NO x in said exhaust stream , with the use of said first additive and said reduction characteristics of said catalytic filter ; - a second oxidation of one or more of nitrogen oxides NO and incompletely oxidised carbon compounds in said exhaust stream , with the use of a second oxidation catalyst , which is arranged downstream of said catalytic filter ; and - a control of supply of a second additive into said exhaust stream , with the use of a second dosage device , arranged downstream of said second oxidation catalyst ; - a second reduction of nitrogen oxides NO x in said exhaust stream , with the use of at least one of said first and said second additive in a reduction catalyst device , arranged downstream of said second dosage device ; <EOS>