Disclosed is a Cu alloy film for a display device that has high adhesion to a glass substrate while maintaining a low electric resistance characteristic of Cu-based materials. The Cu alloy film is wiring in direct contact with a glass substrate on a board and contains 0.1 to 10.0 atomic % in total of one or more elements selected from the group consisting of Ti, Al, and Mg. Also disclosed is a display device comprising a thin-film transistor that comprises the Cu alloy film. In a preferred embodiment of the display device, the thin-film transistor has a bottom gate-type structure, and a gate electrode and scanning lines in the thin-film transistor comprise the Cu alloy film and are in direct contact with the glass substrate.