To select a conductive particle which is inductively charged in a constant electric field, from a conductive particle which is not inductively charge and an insulating particle.

This apparatus is constituted of a carrying and supporting body 7 for supplying a conductive particle 1, a selection electrode 3 supported by a carrying and supporting body 7, an upper part electrode 2 so installed on the opposite to the selection electrode 3 at a gap A as to generate an electric field between the selection electrode 3 and itself and reciprocate the conductive particle 1 along the electric field, a lower part electrode 4 so installed on the opposite to the upper part electrode 2 at a gap A and on the opposite to the selection electrode 3 at a gap B as to generate an electric field between the upper part electrode 2 and itself, a collecting apparatus 5 for recovering the conductive particle 1 reciprocated by the electric field between the upper part electrode 2 and the selection electrode 3, and an electric power source 6 for applying voltage to the upper part electrode 2 and the apparatus is further provided with an air current generating means (not illustrated in the figure) for generating air current in an air flow path C.