PURPOSE: To efficiently classify stock particles without changing the characteristics thereof, by supplying stock particles such as organism cells to a dielectric substrate having a linear electrode group embedded therein and separating the same by the action of a shifting electric field.

CONSTITUTION: A dielectric substrate 1 is a flat plate comprising glass or ceramics and has a large number of linear electrodes 2aW2n embedded therein so as to be arranged on the same plane in parallel to each other at a constant interval and the electrodes are successively connected to the terminals of a three-phase AC power source so that the electrodes come to the same phase two electrodes apart. The dielectric substrate 1 is arranged so as to be inclined to a horizontal surface and, when a three-phase AC power source is applied to the group of the linear electrodes 2aW2n in such a state that the supply apparatus 20 of stock particles 9 is provided above the substrate 1, a shifting electric field 12 advancing so as to traverse the longitudinal direction of the linear electrode group is generated on the surface of the substrate 1. Whereupon, the stock particles 9 receive the shifting electric fields 12aW12c and the effect of gravity corresponding to the characteristics thereof to be dispersed to discharge parts.