A piezoelectric device for use in a liquid ejecting head configured to eject a liquid from a nozzle, comprising: a flow-path-forming substrate in which an individual liquid chamber that communicates with the nozzle and a liquid supply chamber that communicates with the individual liquid chamber are formed, a vibration plate formed at a position corresponding to the individual liquid chamber and the liquid supply chamber of the flow-path-forming substrate, a plurality of liquid supply ports formed to communicate with the liquid supply chamber, and a piezoelectric element including a first electrode, a piezoelectric layer, and a second electrode, the piezoelectric element being formed at a position on the vibration plate corresponding to the individual liquid chamber, wherein the liquid supply ports are provided so as to penetrate the vibration plate, wherein the vibration plate contains zirconium oxide, and characterized in that the piezoelectric layer is covered with a protective film, wherein the plurality of liquid supply ports are positioned between a communication portion of the liquid supply chamber and a manifold, and the vibration plate and the protective film are stacked in the region between the communication portion of the liquid supply chamber and the manifold, the vibration plate comprises a first film having a compressive internal stress and a second film having a tensile internal stress, the first film is one of an insulating film comprising zirconium oxide formed by a liquid phase method and an elastic film, the second film is an insulating film comprising zirconium oxide, in the case that the first film is an insulating film comprising zirconium oxide formed by a liquid phase method, the second film is an insulating film comprising zirconium oxide formed by a vapor phase method, and the first film is formed on the flow-path-forming substrate and the second film is formed on the first film, whereby an internal stress of the vibration plate around the liquid supply ports is substantially neutral. a flow-path-forming substrate in which an individual liquid chamber that communicates with the nozzle and a liquid supply chamber that communicates with the individual liquid chamber are formed, a vibration plate formed at a position corresponding to the individual liquid chamber and the liquid supply chamber of the flow-path-forming substrate, a plurality of liquid supply ports formed to communicate with the liquid supply chamber, and a piezoelectric element including a first electrode, a piezoelectric layer, and a second electrode, the piezoelectric element being formed at a position on the vibration plate corresponding to the individual liquid chamber, wherein the liquid supply ports are provided so as to penetrate the vibration plate, wherein the vibration plate contains zirconium oxide, and characterized in that the piezoelectric layer is covered with a protective film, wherein the plurality of liquid supply ports are positioned between a communication portion of the liquid supply chamber and a manifold, and the vibration plate and the protective film are stacked in the region between the communication portion of the liquid supply chamber and the manifold, the vibration plate comprises a first film having a compressive internal stress and a second film having a tensile internal stress, the first film is one of an insulating film comprising zirconium oxide formed by a liquid phase method and an elastic film, the second film is an insulating film comprising zirconium oxide, in the case that the first film is an insulating film comprising zirconium oxide formed by a liquid phase method, the second film is an insulating film comprising zirconium oxide formed by a vapor phase method, and the first film is formed on the flow-path-forming substrate and the second film is formed on the first film, whereby an internal stress of the vibration plate around the liquid supply ports is substantially neutral.