Copolymer and production method therefor

Provided is a photoreactive azide-containing copolymer having sufficient biocompatibility for use in medical material applications. Further provided is a production method that enables the photoreactive azide-containing copolymer to be stably supplied on an industrial scale. It has been discovered that a photoreactive azide-containing copolymer can be synthesized according to a method that enables a stable supply on an industrial scale as a result of utilizing a polymer reaction between a glycidyl-containing copolymer and azidobenzoic acid, leading to the completion of the present invention.