PURPOSE: To prevent a thin workpiece from sticking onto an automatic barrel machining device by providing a synthetic resin particle feed device above a hopper so as to charge synthetic resin particles into the hopper, and by bonding synthetic resin rods to a charged material passage such as a chute.

CONSTITUTION: A workpiece fed from a workpiece casing 10 into a hopper 3 is fed into a barrel tank from the outer cylinder 4 of a chute through a bucket 9, an upper hopper 22 and an upper chute 23. Synthetic resin particles are fed into the hopper 3 together with the workpiece from a synthetic resin particle constant amount supply device 12 arranged above the hopper 3 so that it is possible to prevent the workpiece from sticking to another workpiece. Further, synthetic resin round rods are laid closely to each other and bonded on the inner surfaces of the chute of the hopper 3, the outer cylinder 4 of the chute, the bucket 9, the upper hopper 22, and the chute 23 and the like, thereby it is possible to prevent the workpiece from sticking onto these chutes of the like.