An apparatus for opening and cleaning fiber tufts, includes an opening roll, a feeding mechanism for advancing the fiber tufts to the opening roll; a screen disposed along one part of the circumferential surface of the opening roll and located downstream of the feeding mechanism, as viewed in the direction of rotation of the opening roll. The screen permits impurities, propelled by centrifugal forces, to pass therethrough. The screen is eccentric with respect to the opening roll. There is further provided a shroud disposed along one part of the circumferential surface of the opening roll and located downstream of the screen. The shroud is movably supported for assuming an open position in which fiber tufts may pass from an annular clearance between the opening roll and the screen to an outlet and a closed position in which passage of the fiber tufts is blocked from the clearance to the outlet.