PURPOSE: To produce a lens and a frame unit so as to have different colors by forming the air passage communicating with a vacuum pump and forming a raw material passage infecting molten raw material into a frame forming space to one of first and second casting mold structures.

CONSTITUTION: A lens receiving space is formed between a support surface 311 and a supplementary surface 321 and the protruding parts 312 of the support surface 311 are fitted in the cavities 22 on two side parts of the back 22 of a lease unit 2 to prevent the movement of the lens unit 2. A frame forming gap is formed between first and second frame defining surfaces 314, 322. A vacuum pump 4 is connected to an air passage 313 and, when the lens unit 2 is received in the lens receiving space, air is discharged form the air passage 313 to fix the lens unit 2 to the support surface 311 under suction. In this state, a weighted molten raw material is injected into the frame forming space of a coasting mold 3 form a raw material passage 33 is this state to integrally mold frame unit at the predetermined place of the lens unit 2.