PURPOSE: To carry out sorting in a large treating amount within a short time by a method wherein a sorting stage is used as an earth electrode and a DC high voltage electrode is provided above the sorting stage to carry out the sorting by Coulomb force and gravity.

CONSTITUTION: A sorting stage 11 having a partition provided to the outer periphery thereof is used as an earth electrode and a DC high voltage electrode 21 comprising a flat plate like electrode is provided above the sorting stage 11. In this condition, a bridged substance is shaken off to the outer periphery of the sorting stage 11 by Coulomb force generated by applying DC high voltage to the DC high voltage electrode 21 and gravity. By this method, the recovery of pure compost particles is fastened and a large amount thereof can be treated within a short time.