PURPOSE: To easily and inexpensively mold a chamfer shape to a pulley by using metal molds.

CONSTITUTION: This pulley molding device has an upper mold part 12 and lower mold 14 which are parted apart a prescribed spacing and are displaced relatively to each other, a molding core 18 which is disposed freely displaceably in this upper mold part 12, a dummy core 36 which is disposed in the lower mold part 14 coaxially with this molding core 18 and is displaced integrally with the molding core 18 at the time of pressurization and a cylinder mechanism 40 which displaces the dummy core 36 stepwise along the axial line direction. A stepped part 30 having a slope 32 corresponding to the chamfer shape of the inner peripheral surface of the pulley is formed at the molding core 18.