Abstract: A magnetic separator useful for treating chips in a machine tool is disclosed, which comprises a separating cylinder, a plurality of magnetic plates arranged at an outer periphery of the cylinder and spaced apart each other, an inlet for a fluid suspension at a middle part of the cylinder, outlets for a separated fluid at one end and for the suspended matter, such as machined chips, at the other end of the cylinder, and a screw conveyor inserted into the cylinder in such a way that the screw conveyor is contacted at its peripheral edge with an inner wall of the cylinder. The magnetic plates are arranged in a circle around the cylinder with the polarity of the adjacent magnetic plates arranged in a special sequence for generating a maximum magnetic flux toward the axial center of the cylinder. Also, the magnetic plates extend from the inlet near the middle of the cylinder to both outlets at opposite ends of the cylinder for achieving a strong magnetization of the chips suspended in the fluid.