A piezoelectric device and a manufacturing method thereof in which a piezoelectric film formed of a thin film of a lead zirconate titanate-based perovskite oxide is formed on a substrate, and at least a first region out of the first region and a second region of the piezoelectric film is irradiated with electromagnetic waves having a wavelength of 230 nm or less in a reducing atmosphere to provide a difference in piezoelectric characteristics between the first region and the second region so that the first region has a smaller absolute value of a piezoelectric constant d31 and a smaller dielectric loss tan δ than the second region.