An exhaust gas treatment device for an exhaust system of an internal combustion engine, preferably of a motor vehicle, having a housing which encloses an exhaust gas treatment chamber, wherein - a mixing element is provided, which divides the exhaust gas treatment chamber into an upstream-side inlet region and a downstream-side through-flow region, - the housing has on the inlet side at least one inlet (12, 13), which is open towards the inlet region, for attaching at least one exhaust gas feed line (2, 3), - the mixing element has at least one first input opening which connects the inlet region fluidically to the through-flow region and faces a first side of the inlet region, - the mixing element has at least one second input opening which connects the inlet region fluidically to the through-flow region and faces a second side of the inlet region - characterized in that - the housing has on the inlet side a first inlet for attaching a first exhaust gas feed line, which inlet is open towards the inlet region and is arranged on the first side of the inlet region, - the housing has on the inlet side a second inlet for attaching a second exhaust gas feed line, which inlet is open towards the inlet region and is arranged on the second side of the inlet region, - the first side and the second side of the inlet region are spaced apart from each other transversely to the longitudinal direction of the housing and are opposite each other, in particular diametrically, - the first side is opposite the second side in a spacing direction and that the at least one first input opening and the at least one second input opening are arranged offset to each other transversely to the spacing direction, - the mixing element has at least one depression on its side facing the inlet region, which depression forms a flow channel which leads to one of the input openings (22, 23), wherein it can in particular be provided for at least one such flow channel to run substantially parallel to the spacing direction, - the mixing element has at least one perforation region, which has a perforation, wherein the perforation region in particular runs outside the at least one depression. - a mixing element is provided, which divides the exhaust gas treatment chamber into an upstream-side inlet region and a downstream-side through-flow region, - the housing has on the inlet side at least one inlet (12, 13), which is open towards the inlet region, for attaching at least one exhaust gas feed line (2, 3), - the mixing element has at least one first input opening which connects the inlet region fluidically to the through-flow region and faces a first side of the inlet region, - the mixing element has at least one second input opening which connects the inlet region fluidically to the through-flow region and faces a second side of the inlet region - characterized in that - the housing has on the inlet side a first inlet for attaching a first exhaust gas feed line, which inlet is open towards the inlet region and is arranged on the first side of the inlet region, - the housing has on the inlet side a second inlet for attaching a second exhaust gas feed line, which inlet is open towards the inlet region and is arranged on the second side of the inlet region, - the first side and the second side of the inlet region are spaced apart from each other transversely to the longitudinal direction of the housing and are opposite each other, in particular diametrically, - the first side is opposite the second side in a spacing direction and that the at least one first input opening and the at least one second input opening are arranged offset to each other transversely to the spacing direction, - the mixing element has at least one depression on its side facing the inlet region, which depression forms a flow channel which leads to one of the input openings (22, 23), wherein it can in particular be provided for at least one such flow channel to run substantially parallel to the spacing direction, - the mixing element has at least one perforation region, which has a perforation, wherein the perforation region in particular runs outside the at least one depression.