An SCR exhaust aftertreatment device of an internal combustion engine, containing an injector for injecting a reductant, a mixing unit and an SCR catalytic converter disposed immediately downstream in the direction of exhaust flow, wherein the mixing unit exhibits a swirl element and an impact element positioned upstream of the swirl element in the direction of exhaust flow, whereby the swirl element is configured of two guide elements disposed inside one another and swirl vanes for creating a swirling motion are disposed in an inner guide element and swirl vanes, which create a counterswirling motion, are disposed between the inner guide element and the outer guide element.