A part-processing machine having, in series, consecutive parts on a belt (2) moving same along a main conveying line. Selectively identified non-compliant parts are removed from the conveying line, into a transfer device (1) by pickup tools (8) supported on the periphery of a rotating drum (6) mounted transversely to the conveying line and arranged to rotate about itself so as to pass over the belt, enabling the non-compliant parts to be picked up by the pickup tools and released once the parts have been transported away from the conveying line. The pickup tools have pneumatic gripping heads, more particularly for example suction cups. The pneumatic gripping heads are depressurized relative to the surrounding air by a low-pressure chamber provided inside the drum, to which each head is connected by a tube inside a tool support arm.
