PURPOSE: To provide an apparatus for separating foreign bodies from a fiber flock stream that can be used inside the spinning preparation, particularly in the places where the air flow ratio fluctuates in the conduit for transferring the materials.

CONSTITUTION: The apparatus for separating foreign bodies from cotton fiber flocks in spinning preparation comprises a pneumatic conduit (9) which leads through an inlet conduit (10) to a separating zone providing a deflection of the air stream (9a, 9b), an outlet conduit (11) removing the cleaned fiber material where at least one opening is formed in the separation zone. The air flow in the inlet conduit (10) and separating zone is regulated, for example, using an air branch line (14), the quantity of air in the line (14) being adjusted as by an adjustable throttle (15) in dependence upon the quantity of air flowing through the inlet conduit (10).