PURPOSE: To secure positioning accuracy and prevent breakage of a carrying arm and deformation of forming lens by providing a stopper pin and a columnar projection in carrying direction of the carrying arm in a glass forming device for placing and supporting an optical glass raw material on a carrying arm and carrying in and out a heating furnace and a forming chamber.

CONSTITUTION: An engaging and contacting part 62 is provided in a carrying arm 12 placing a glass raw material on the top. A columnar projection part 63 and a stopper pin 64 are projectingly installed in a carrying direction of the carrying arm 12 in the engaging and contacting part 62. One sides, a stopper 65 is provided opposite to the engaging and contacting part 62 in a forming chamber in which upper and lower forming molds are provided. A rectangular notch part 67 for supporting the lower surface of the columnar projection part 63 is provided in the stopper 65 and simultaneously a V-shaped notch part 66 which comes into contact with the top of the stopper pin 64 is provided in the stopper 65. When the stopper pin 64 is brought into contact with the V-shaped notch part 66, axial center of upper and lower forming shafts are allowed to coincide with axial center of upper and lower forming shaft. Deflection of the carrying arm in forming can be prevented by supporting the columnar projection part 63 with the rectangular notch part 67.