A static mixer for mixing exhaust gases (10, 20), the static mixer comprising: a gas accommodation part (100, 200) comprising: - a first gas accommodation part having a first inlet formed on the top of the first gas accommodation part with a first slant surface and configured to introduce a first gas into the static mixer, and - a second gas accommodation part having a plurality of second inlets with second slant surfaces, wherein the second inlets are partitioned from each other and separated from the first inlet to form separate flow paths for a second gas being introduced into the static mixer, so that due to the first slant surface and the second slant surfaces the first and second gas (10, 20) having different temperatures when introduced through the first inlet and the plurality of second inlets flow out of the gas accommodation part (100, 200) to a plurality of divided sections (111, 211); a discharge part communicating with the plurality of divided sections (111, 211) to collect and discharge the first and second gas (10, 20), the discharge part including a hollow portion (310, 320, 330); and a mixing plate part having a plurality of unit plates (411, 412) disposed on the upper and lower portions of the hollow portion (310, 320) of the discharge part in such a manner as to have a predetermined angle with respect to flow directions of the first and second gas (10, 20) discharged. a gas accommodation part (100, 200) comprising: - a first gas accommodation part having a first inlet formed on the top of the first gas accommodation part with a first slant surface and configured to introduce a first gas into the static mixer, and - a second gas accommodation part having a plurality of second inlets with second slant surfaces, wherein the second inlets are partitioned from each other and separated from the first inlet to form separate flow paths for a second gas being introduced into the static mixer, - a first gas accommodation part having a first inlet formed on the top of the first gas accommodation part with a first slant surface and configured to introduce a first gas into the static mixer, and - a second gas accommodation part having a plurality of second inlets with second slant surfaces, wherein the second inlets are partitioned from each other and separated from the first inlet to form separate flow paths for a second gas being introduced into the static mixer, so that due to the first slant surface and the second slant surfaces the first and second gas (10, 20) having different temperatures when introduced through the first inlet and the plurality of second inlets flow out of the gas accommodation part (100, 200) to a plurality of divided sections (111, 211); a discharge part communicating with the plurality of divided sections (111, 211) to collect and discharge the first and second gas (10, 20), the discharge part including a hollow portion (310, 320, 330); and a mixing plate part having a plurality of unit plates (411, 412) disposed on the upper and lower portions of the hollow portion (310, 320) of the discharge part in such a manner as to have a predetermined angle with respect to flow directions of the first and second gas (10, 20) discharged.