Heat exchanger comprising: first fluid inlets, first fluid outlets, second fluid inlets and second fluid outlets, each of the first fluid inlets, the first fluid outlets, the second fluid inlets and the second fluid outlets being arranged on four different sides of a heat exchanger core; a manifold covering one of the four different sides of the heat exchanger core, wherein a first sidewall of the manifold is arranged at an angle smaller than 90 degree to the one side of the heat exchanger core which is covered by the manifold, characterized in that an edge of the heat exchanger core between the one side of the heat exchanger core which is covered by the manifold and a neighbouring side of the four different sides of the heat exchanger core forms a common weld line with a connecting edge of the first sidewall of the manifold, and in that the heat exchanger comprises a stack of heat transfer plates, wherein first flow channels and second flow channels are provided in between the heat transfer plates by arranging spacing elements (11, 14) between the heat transfer plates, the spacing elements extending along four edge parts of the heat transfer plates leaving open the first fluid inlets, the first fluid outlets, the second fluid inlets and the second fluid outlets, wherein the spacing elements are welded to the heat transfer plates along the four edge parts forming a heat exchanger core, and wherein the edge of the heat exchanger core forming the common weld line with the connecting edge of the manifold is one of four edges extending along and formed by the entirety of the stacked heat transfer plates with spacing elements in between. first fluid inlets, first fluid outlets, second fluid inlets and second fluid outlets, each of the first fluid inlets, the first fluid outlets, the second fluid inlets and the second fluid outlets being arranged on four different sides of a heat exchanger core; a manifold covering one of the four different sides of the heat exchanger core, wherein a first sidewall of the manifold is arranged at an angle smaller than 90 degree to the one side of the heat exchanger core which is covered by the manifold, characterized in that an edge of the heat exchanger core between the one side of the heat exchanger core which is covered by the manifold and a neighbouring side of the four different sides of the heat exchanger core forms a common weld line with a connecting edge of the first sidewall of the manifold, and in that the heat exchanger comprises a stack of heat transfer plates, wherein first flow channels and second flow channels are provided in between the heat transfer plates by arranging spacing elements (11, 14) between the heat transfer plates, the spacing elements extending along four edge parts of the heat transfer plates leaving open the first fluid inlets, the first fluid outlets, the second fluid inlets and the second fluid outlets, wherein the spacing elements are welded to the heat transfer plates along the four edge parts forming a heat exchanger core, and wherein the edge of the heat exchanger core forming the common weld line with the connecting edge of the manifold is one of four edges extending along and formed by the entirety of the stacked heat transfer plates with spacing elements in between.