The piezoelectric device includes a substrate, a first electrode deposited on the substrate, a piezoelectric film deposited on top of at least a part of the first electrode by vapor phase deposition, a second electrode deposited on the piezoelectric film and having a water vapor transmission rate of not more than 1 g/m2/day, and at least one protective film that covers at least peripheries of the second electrode and the piezoelectric film and which has an opening in a position corresponding to the piezoelectric film except the periphery thereof. The piezoelectric device has satisfactory moisture resistance and is capable of effectively preventing the ingress of moisture into the piezoelectric film.