The magnet roll according to the present invention comprises (a) first and second shafts rotatable around the same axis relative to each other; (b) a permanent magnet member fixed around the second shaft and having a plurality of magnetic poles extending along the axis of the second shaft on its outer surface; (c) a first flange member connected to the first shaft and rotatably supporting one end of the second shaft; (d) a second flange member rotatably supported by the second shaft; (e) a hollow cylindrical sleeve made of a plastically deformable non-magnetic material and fixed to the first and second flange members on both ends such that it encircles the permanent magnet member rotatably relative to the permanent magnet member; and (f) an inner diameter-increased area provided in each side end portion of the sleeve, which receives each flange member and is folded inward over each flange member to fix the sleeve to each flange member.