PURPOSE: To obtain an amorphous body having a spiral shape or the like by providing a rotary disc having a circular conical surface so as to face a quartz nozzle disposed in the lower part of an electric furnace.

CONSTITUTION: An electric furnace 11 has an electric heater 3 circumnutating around a crucible 2 and a heat insulating cylinder and is disposed with a quartz nozzle 12 in the lower part thereof. A rotary disc 14 is provided below the nozzle 12 in such a way that the outside circumferential surface faces a discharge port 13. Said outside circumferential surface forms the circular conical surface B having the same angle θ of inclination as the angle of inclination of the port 13 and is fixed to a revolving shaft 7. The nozzle 12 is so constituted as to diverge toward the larger diameter side of the disc 14 having a size D1. The discharge flow rate of the nozzle 12 is larger toward the large diameter part of the disc 14 but a uniform thickness is obtd. by contact with the large diameter part having the higher circumferential speed. The spiral amorphous steel plate is thus easily obtd.