The piezoelectric thin film resonator, piezoelectric Dünnfilmresonatorfilter and manufacturing processes for these

The present invention is to provide an element structure which can prevent mixing of impurities inside the respective layers which configure a resonator and a manufacturing method thereof. Thus, it is the object of the present invention, a bulk acoustic wave piezoelectric thin film resonator, a bulk acoustic wave piezoelectric thin-film resonator and a thin film-tuning fork shape Zerroszillator to obtain that can realize a higher Q value due to an improvement in the film quality. A piezoelectric thin-film resonator includes: a piezoelectric thin film; a layer structure that includes a first metal electrode film and a second metal electrode film, which enclose at least a portion of the piezoelectric thin film, and formed on a substrate; and an acoustic-insulating layer formed on the substrate at a position corresponding to the layer structure, wherein the first metal electrode film is formed on the substrate and the second metal electrode film is formed on the first metal electrode film while sandwiching the piezoelectric thin film is sandwiched, and a to the second layered metal electrode film protective film is provided to cover the second metal electrode film.