The invention relates to 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 said conveying line into a transfer device (1) by means of 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 said pickup tools and released once they have been transported away from the conveying line. The pickup tools have pneumatic gripping heads more particularly for example suction cups. Said pneumatic gripping heads are depressurized relative to the surrounding air by means of a low pressure chamber provided inside the drum to which each head is connected by a tube inside a tool support arm.