In a molding apparatus in which upper and lower dies are held in a bearing, there are provided pipes for introducing N2 gas used for controlling temperatures of balls of the bearing, whereby difference in temperature between the guide member and the upper and lower dies is controlled. With this structure, it is possible to prevent generation of an excessive compressive force between the upper die and the lower die and the bearing, to thereby prevent breakage of the dies. Further, it is also possible to prevent formation of gaps between the upper die and the lower die and the bearing, to thereby mold an optical element excellent in accuracy of an optical axis.