Abstract: An application to a resin material and a polymerization method of a polymerization agent having a polymerizable surface structure and a mechanism of supplying the polymerization agent, the polymerization agent exhibiting a polymerizing function in contact with the surface of the resin material. The resin material is obtained by living radical polymerization of a radical polymerization initiator exhibiting living property and an unsaturated monomer capable of radical polymerization with the polymerization initiator. The polymerization agent is brought into in contact with the surface of the resin material to induce radical re-polymerization of the polymerization agent. As a result, a damaged portion of the resin material can be repaired or the resin materials can be bonded to each other by way of the polymerization agent, which can suppress formation of the hetero-interface or improve the service life of the resin material.