To solve such a problem that the broken piece or tacky matter of an adhesive tape is mixed with a photosetting plastic lens raw material at opening of an injection port to lower the production yield of a plastic lens for spectacles in s conventional method wherein a mold is formed from the adhesive tape and a mold in a photosetting resin lens polymerizing method and the joint of the adhesive tape is peeled to inject a photosetting plastic lens raw material and the adhesive tape is again bonded or an injection needle is allowed to pierce through the adhesive tape to inject the photosetting plastic lens raw material in the mold.

The photosetting plastic lens raw material is injected and subsequently irradiated with light to be cured. An injection port can be formed even if the adhesive tape is not wound around an entire periphery to dispense with work peeling the adhesive tape in order to inject the photosetting plastic lens raw material to again bond the same. Further, when the injection needle is allowed to pierce through the adhesive tape, the mixing of the broken piece of tacky matter with the photosetting plastic lens raw material can be prevented.