PURPOSE: To separate a powdery body in response to its charged electricity, by supplying the powdery body to be sorted to a rotary charger, forming frictional charging by the collision of particles against the rotary body, and introducing the charged powdery body into a sorting chamber in which a DC electric field is formed by a couple of parallel-plate electrodes.

CONSTITUTION: In the apparatus for separately sorting a mixed powdery body comprising two or more different kinds of components into every specified component, the amount of a powdery body sent out from a quantitative feeder 4 is held at a predetermined value corresponding to the number of rotation of the rotary body of a charger 5. At said charger 5, a rotary body 52 to be rotated at a high speed and a powdery body-supplying means 53 for bringing the particles of the powdery body to be sorted into collision with the surface of said rotary body to provide said particles with frictional electricity are provided. In addition, at an electrostatic separating part 9, a couple of electrodes 901, 902 on which DC voltage is impressed are provided, so that charged particles supplied from the charger 5 to a space between said electrodes is separated in response to their charged polarity. By this method, the step of treating, dehydrating or drying sludge can be omitted or simplified.