A feeding device, particularly for feeding powdered materials into a device processing the same, in particular an extruder, the feeding device including a housing with a receiving region for receiving the material, which is movable laterally over at least one flexible wall, which is movable by at least one moving mechanical element acting thereon, wherein the element is movable along the wall. The wall exterior has bumps, is moved via the element, and/or the element is non-round in its motion.