PURPOSE: To carry out separation in high precision by a simple structure, by a method wherein a powdery substance to be sorted is supplied to a rotary blade type charging apparatus to be charged by friction and the charged powder is introduced into a sorting chamber in which a D.C. electric field is generated by parallel flat plate electrodes.

CONSTITUTION: When a powdery substance to be sorted ground to a fine powdery form is supplied to a rotary blade type charging apparatus 5, powder particles repeat collision with a rotor and the wall of said apparatus 5 by a revolving gas stream generated by the rotor in said apparatus 5 to generate friction charge. In the next step, the charged particles are sent to be electrostatic separation chamber 9 in which a D.C. electric field is generated by parallel flat plate electrodes to be accelerated and separated and collected corresponding to a charge amount and polarity. As is apparent from the foregoing, highly precise separation is carried out at low cost in a simple apparatus without using water.