The invention relates to a method and to a device for identifying and removing foreign matter in fiber material in several stages, which is characterized in that the sensor systems react to foreign matter of the same type. When distributed across a conveyor path (2), various sensor systems (4, 4', 4') and the pertaining removal devices (5, 5', 5') are thus capable of removing foreign matter (7, 7', 7') that may optionally have different sizes. The individual removal stages are advantageously positioned along the conveyor path in such a manner that the increasing dissolution degree of the fiber material and the concurrent diminution of the fiber substances are taken into consideration in an optimum manner.