PURPOSE: To obtain a photosensitive resin dyeable at a low temp. in a short time and giving a color separating filter by copolymerizing a specified chalcone compound with a monomer having the structure of tertiary amine and a polymerizable unsatd. bond.

CONSTITUTION: At least one kind of 4'-methacryloyloxychalcone and 4-methacryloyloxychalcone is copolymerized with a monomer having the structure of tertiary amine and a polymerizable unsatd. bond such as (meth)acrylamide, dimethylmethacrylamide or dimethylaminopropylmethacrylamide to obtain a photosensitive resin with high dyeability and resolution. The resin can be dyed at a low temp. in a short time. Since the resin is formed into a deeply dyeable thin film, the resolution is increased, and pattern matching is facilitated. Pollution controlling equipment is not required, the cost of the manufacture of a color separating filter can be reduced, and the resin causes no dark reaction and can be used stably.