PURPOSE: To insert correctly a magnet without mistaking its polarity and to automate the loading of the magnet by sucking a magnet supplied to a position close to the insertion hole of a disc by a guide pin enabled to ascend/ descend and guiding the magnet to the insertion hole.

CONSTITUTION: The titled device is provided with a pallet 40 on which the rotary disc 2 is placed, a lifting means 50 arranged downwards the pallet 40 to ascend/descend the magnets 54, 55 and a feeding means 60 for supplying PG mangets 3. Each PG magnet 3 is supplied to a position close to the insertion hole 2a one by one by the rotation of a sliding plate 63. Sebsequently, the magnets 54, 55 are ascended/descended by one rotation of a cam 59 of the lifting means 50 and the guide pin 43a is magnetized to such the magnet 3, guide and load the magnet 3 to the insertion hole 2a, then erased at its magnetism. Consequently, the magnet 3 is prevented from inserting incorrectly its polarity, and the loading of the magnet is automated.