To provide a high-productivity surface treatment method for a norbornene resin which eliminates polishing a surface to be coated or attached or letting it stand over a long period of time, which improves the spread of a coating film on the occasion of coating, and which makes a sufficient adhesive performance to be demonstrated efficiently when a joining with another adherend is carried out.

The surface treatment method for a norbornene resin molding obtained by reaction injection molding comprises the first step wherein the surface of the norbornene resin molding is treated with an organic solvent containing at least one ketone solvent or ester solvent, the second step wherein the surface of the resin molding is subjected to energy ray irradiation processing, and optionally the step wherein the surface of the resin molding is coated with a primer, and all the steps are completed within 120 hours after the finish of the reaction injection molding.