Abstract: In a device for opening and cleaning fiber material with two opener rolls (2,4) rotating in the same direction and each being supported in a housing (3) side by side in parallel in a horizontal plane above grate segments (12, 14). The circles of action of the rolls almost contact in the horizontal, with a feeder (8) directed tangentially onto the one end of the first opener roll (2) in the fiber transport direction An outlet (30) protrudes horizontally from the housing (3) on the side of the housing (3) opposite the feeder (8) , through which an air flow (6, 34) feeds and discharges the fiber material, respectively. It is provided that, via the feeder (8), the fiber material is directed vertically from above between the housing (3) and the opener roll (2) onto that side of the first opener roll (2) facing away from the second opener roll (4).