Alkali-niobate-based piezoelectric thin film element

An alkali-niobate-based piezoelectric thin film element comprising:

• a substrate;
• a lower electrode film on the substrate;
• a piezoelectric thin film on the lower electrode film, the piezoelectric thin film comprising an alkali-niobate-based piezoelectric material represented by the formula (NaxKyLiz)NbO3, where 0≦x≦1, 0≦y≦1, 0≦z≦2, and x+y+z=1;
• and
• an upper electrode film on the piezoelectric thin film, wherein
• the piezoelectric thin film has a desired micro pattern formed for a piezoelectric element and contains a metal element in a higher concentration near the upper electrode film than near the lower electrode film, the metal element being chromium, gold or platinum, and
• the average concentration of the metal element is 5×1017 atoms/cm3 or less in a region within ±15% of the thickness of the piezoelectric thin film from a position corresponding to half the thickness of the piezoelectric thin film.