PURPOSE: To enhance production efficiency and to prevent the lowering of surface magnetic flux density by providing a roll made of a nonmagnetic material having a magnetic pole pair and a permanent magnet embedded therein to the periphery of the molding cavity of a mold and injecting a molten resin magnet material in the mold and taking out the roll while applying orienting lines of magnetic force to cool and solidify the same.

CONSTITUTION: A roll 12 is inserted in the mold cavity 13 formed by the fixed mold 15 and movable mold 16 of a mold and magnetic members 8, 10 and 11, 9 being magnetic pole pairs becming respectively poles for starting and terminating orienting lines of magnetic force are embedded in the roll 12. Nonmagnetic members 6, 7 and permanent magnets 1, 2 are successively embedded between the magnetic pole pairs from the side of a molding cavity 23 molding a magnet roller 3. When a resin magnet material is injected into the molding cavity 23, a magnetic powder is oriented by the orienting lines of magnetic force of the magnetic members 8-11 to form two magnetic pole pairs. After dwelling, the mold is opened before the resin is perfectly cooled and solidified to take out the roll 12. After the roll 12 is further cooled, the magnet roller 3 is taken out of the roll 12.