Polyglycolic acid (PGA) used for this study is categorized as a polyester resin comprising hydrogen, carbon, and oxygen. The usage of PGA in electronic parts such as printed circuit boards has an important role in the protection of environment, but several difficulties must be overcome. For this study, an Ar^＋ ion beam was used to modify a PGA surface so that the metal-film-coated PGA durability was improved. Then double-layer Cu/Ti films were deposited on the modified PGA using vacuum evaporation. Results showed that the Ti layer between the Cu film and the surface-modified PGA exhibited superior adhesion and electrical conductivity compared to those of a Cu single-layer film. Those properties showed a maximum value at 30 nm Ti thickness, but deteriorated with increasing Ti-layer thickness. Electrical conductivity measurements suggest the possible use of PGA for printed circuit boards.