Method for manufacturing press-molded glass object

In press molding, a shaft (metal mold 13) is moved by positional or torque control to cause upper and lower molds to reach a set position slightly before a position where the upper and lower molds are set in a final mold closed state. As soon as the upper and lower molds reaches the set position, the control is switched to torque control using a small force which does not deform a glass material to perform feedback control. For this reason, when the cooling process is started, the mobile shaft is moved by the same amount as a contraction amount of the shaft, the actual position of the shaft is moved. However, a tight contact state between the molds and the glass material is kept without changing the thickness of the glass material, and positional control and torque control can be apparently performed at once. Thereafter, when temperature reaches an almost glass transition point, final pressing is performed. A position where the material is press-molded is exactly controlled by correcting an origin position of lower mold by closing the molds before press-molding. According to this method, a highly accurate optical element having thickness reproducibility can be obtained.