PURPOSE: To enhance sorting and treating capacities by treating an electroconductive particle and an insulative particle in a mixture to be sorted by a corona discharge electrode and a flat plate like electrode to separate them electrically.

CONSTITUTION: DC high voltage is applied to the corona discharge electrode 20 and the corona discharge electrode 21 and the flat plate like electrode 22 forms a corona discharge electric field I and a high intensity electric field II between a space with a sorting stage 10 of an earthed electrode. A mixture comprising an electroconductive particle O and an insulative particle N is supplied to a channel 14 of the sorting stage 10 by a feeder 30. The mixture M receives a large amount of a positive ion shower in the electric field I and the insulative particle N is positively charged to be held in the channel 14 and the electroconductive particle O discharges a positive ion to the sorting stage 10 to be negatively charged. Subsequently, the particle O is attracted to and collided with the flat plate like electrode 22 by Coulomb force and, after repeats attraction→dischrge→dropping, passes over a partition fence 13 to be collected to a side flange of a belt 12 positioned along an external side of the channel 14. Thereby, both of them are sorted.