In a method of manufacturing a piezoelectric device, among a +C plane on a +Z axis side of a piezoelectric thin film and a −C plane on a −Z axis side of the piezoelectric thin film, the −C plane on the −Z axis side of the piezoelectric thin film is etched. Thus, −Z planes of the piezoelectric thin film on which epitaxial growth is possible are exposed. Ti is epitaxially grown on the −Z planes of the piezoelectric thin film in the −Z axis direction such that the crystal growth plane thereof is parallel to the −Z planes of the piezoelectric thin film. Al is then epitaxially grown on the surface of the Ti electrode in the −Z axis direction such that the crystal growth plane thereof is parallel to the −Z planes of the piezoelectric thin film.