PURPOSE: To perform the classification of particles with high accuracy, by supplying particles to be classified to the electric field matrix, formed by a method wherein two sets of linear electrodes are superposed and intersected to each other in an insulated state and AC voltage is applied between electrodes against gravity.

CONSTITUTION: In a particle classifying apparatus, at least two sets of electrode groups each consisting of a plurality of linear electrodes 1 provided in parallel are superposed and the linear electrodes 1 are mutually intersected in an insulated state and an AC power source 3 is connected between the linear electrodes 1 to form an electric field matrix 4. When particles to be classified are supplied to the electric field matrix 4 against gravity, coarse particles naturally fall under gravity and relatively fine particles can approach the electric field matrix 4. Because the lines of electric force alternatively changes in its direction in the electric field matrix 4, particles with a particle size equal to or more than a certain size vibrate along the line of electric force to be forced back to the direction of gravity and only fine particles can pass through fine holes.