Provided is a method of manufacturing a polymer array by photolithography in which a molecule containing a photolabile protecting group is reacted with a surface of a substrate, and then a photosensitizer is coated on the surface of the substrate together with a coating material and the resulting substrate is exposed to light to perform a photochemical reaction. Even by using conventional semiconductor equipment and compounds without separately fabricating light exposure equipment or synthesizing a compound, a polymer array may be effectively manufactured by photolithography with lower exposure energy (shorter period of time).