PURPOSE: To separate parts, particulates and chips in layers and to simplify separation work by putting a mixture of the chips and the parts barrel-polished to be separated in a container with the particulates with specific gravity in the middle of those of the chips and the parts and some water and by giving an oscillation to the container.

CONSTITUTION: A container 1 provided with an oscillating device 3 on its bottom is elastically supported on a base 5 through springs 4, 4, and in this container 1, fine particulates 2 such as glass beads and others are stored with a certain amount of water enough to prevent these particulates 2 from hardening. Thereafter, by putting a mixture of chips and parts barrel-polished in this container and by giving an oscillation by way of driving the oscillating device 3, the aforementioned three are separated in layers in accordance with difference of their specific gravity. That is, they are separated so that the parts the specific gravity of which is the largest come to be in the lowest layer 11, the particulates 2 having the specific gravity in the middles of those of the chips and the parts to be in the middles layer 7 and the chips the specific gravity of which is the smallest to the upper-most layer 12. Thereafter, each of the layers 12, 7, 11 is taken out in sequence, and the parts after barrel polishing are taken out from the layer 11.