The invention relates to an exhaust-gas treatment device (10), comprising a) an outer tube (14) through which an exhaust-gas stream (12) can flow, b) an inner tube (20) that is arranged in a first section (16) of the outer tube (14) and that divides the interior of the first section (16) into a central flow path (22) and a peripheral flow path (24), whereby a first exhaust-gas treatment means (26) is arranged in the central flow path (22) and/or in the peripheral flow path (24), c) means (30, 32) to selectively convey an exhaust-gas stream via the central flow path (22) and/or via the peripheral flow path (24), and d) a second exhaust-gas treatment means arranged in a second section (18) of the outer tube (14) downstream from the first section (16). Flow means (36, 38, 40) are provided that are designed to equalize a flow impinging upon the second exhaust-gas treatment means (28) when the exhaust gas is conveyed via the central flow path (28) as well as when the exhaust gas is conveyed via the peripheral flow path (24).