To provide a device for separating and removing a foreign substance in magnetic powder by which image defects due to the clogging in a developing device and the lowering of the fluidity of a developer caused by the flying of the foreign substance to an image carrying body or the like, by discharging dust and paper powder, which are a non-magnetic body, a developer reduced in resistance or the like from the magnetic powder containing the foreign substance can be prevented.

The device for separating and removing the foreign substance in the magnetic powder is provided with a centrifugal separation means, which has a rotatable non-magnetic pipe body 2 and a magnetic force generator 4 installed inside the non-magnetic pipe body 2 and is for sucking and carrying magnetic powder 6 containing the foreign substance on the non-magnetic pipe body 2 by the magnetic force from the magnetic force generator 4 and for separating the foreign substance in the magnetic powder by the centrifugal force of the rotation of the non-magnetic pipe body 2, and a recovering means 12 for recovering the foreign substance separated by the centrifugal separation means. It is preferably to have a mode provided with a electrostatic separation means having one or more electrodes 14 and 16 mounted to face the non-magnetic pipe body 2 and for separating conductive foreign substance in the magnetic powder 6 by electrostatic force of the electrodes.