PURPOSE: To offer a simple and efficient method for forming optical stock by heating flat glass 12 to a prescribed temp., softening it, flowing out and mounting molten glass 9 on its upper face, cooling it in the process of forming by a pair of dies 13 and 14, generating cracks and obtaining an optical element.

CONSTITUTION: This is a method for forming an optical element in which, in the process of transferring flat glass 12 held to a carrier arm to a pair of dies 13 and 14, it is heated to a prescribed temp. and is reheated; on its upper face, a prescribed amt. of molten glass 9 is placed and is interposingly transferred into the space between the above a pair of dies 13 and 14 ; the flat glass 12 is cooled together with the upper die 13 and the lower die 14 in the process of press forming by the upper die 13 and the lower die 14 from the upper face of the above molten glass 9 to generate strains on the peripheral part of the pressing in the flat glass 12 by the upper and lower dies 13 and 14; by the above strains, cracks are generated; and so that the separation of an optical element as well as the distancing between the upper die 13 and the lower die 14 can be executed.