To provide a thermoplastic adhesive having excellent adhesion performance of a molded resin article and a metallic fixing tool and resistant to the deterioration of the adhesion performance even by the exposure to ultraviolet rays by the outdoor use and provide a metallic fixing tool produced by using the adhesive.

The thermoplastic adhesive composed of a copolymerized polyamide is used for the bonding of a molded resin article for outdoor use to a metallic fixing tool for the article. The main polyamine component of the thermoplastic adhesive composed of a copolymerized polyamide is a compound expressed by general formula (R is H or a 1-4C alkyl; four R groups may be the same or different; Z is H or NH2R', and R' is a 1-4C alkylene group). The metallic fixing tool for the fixing of the molded resin article for outdoor use has an adhesive layer composed of the copolymerized polyamide-based thermoplastic adhesive on the surface of the tool for fixing the molded resin article.