The present invention relates to a mixing and/or evaporating device (12) for an exhaust system (5) of a combustion engine (1), in particular of a motor vehicle, including a support body (19), which encloses a flat cross section through which a flow can flow running transversely to the axial direction (20) of the device (12) in the circumferential direction (32). The support body (19) comprises two long side walls (21, 22) located opposite each other and two short side walls (23, 24) located opposite each other, wherein the short side walls (23, 24) each connect the two long side walls (21, 22) with each other. At least on one long side wall (21, 22) at least on one axial end (26, 27), a plurality of guide blades (25) is arranged. The guide blades (25) stand away in a direction of the other long side wall (21, 22) and are angled relative to the axial direction (20).