The utility model provides a thin film device. The function of the thin film device is not damaged, and the deterioration of the appearance observed from the surface side where the thin film device ismounted is suppressed. The wiring electrode (62) has a planar thin film shape having a first main surface (612) and a second main surface (622) parallel to the surface of the rewiring layer, and a side surface (623) connecting the first main surface (621) and the second main surface (622). The wiring electrode (62) contains copper. The terminal electrode (82) is formed in a first region (R1) of afirst main surface (621) of the wiring electrode (62). The first adhesion layer (92) is made of a material different from copper, and has a shape that continuously covers a second region (R2) of thefirst main surface (621) of the wiring electrode (62) adjacent to the first region (R1) and a side surface (623) of the wiring electrode (62) connected to the second region (R2).