PURPOSE: To release a formed product from dies by forming a spiral wrap between a first forming die by which the rear curve of the spiral wrap is formed and a second forming die by which the front curve of the spiral wrap is formed and by rotating one of the forming dies in the direction in which the phase of the rotated die is increased.

CONSTITUTION: The device consists of a wrap end planar part 11, the wrap rear side forming die 15, the wrap front side forming die 16 and a wrap tip end part (12) and a driving device 20 by which the wrap front side forming die 16 is rotated. The clearance between the die 15 and the die 16 is filled with a molten metal poured from a casting sprue and the metal is solidified. When the die 16 is rotated by the driving device 20, after the metal is solidified in the direction in which the corresponding phase angle of the dies 15 and 16 is increased, the dies are separated from the solidified metal, that is the scroll member. Thus, a draft is eliminated and machining by which a draft part is removed is omitted since the product is separated from the dies.