The present invention relates to a thin-film device whose bump has an improved surface property. A thin-film element of the thin-film device includes at least one of an electromagnetic conversion element, a passive element and an active element. A lead conductor film containing Cu as a main component is connected to the thin-film element. The lead conductor is provided with a bump. The bump includes a first conductor film and a second conductor film. The first conductor film is adhered onto the lead conductor film and is a Ta film or made of a material having a comparably fine crystal structure. The second conductor film is a plated film which is directly or indirectly formed on the first conductor film and contains Au as a main component.