PURPOSE: To decrease the spurious response of a Rayleigh wave to a Sezawa wave, by adding a thin film of a heavy metal such as Au or Ag to an intermediate part between a ZnO film and a sapphire substrate.

CONSTITUTION: The thin film 5 of a heavy metal such as Au or Ag is provided between a substrate 1 and a ZnO film 2 in a surface acoustic wave element comprising the sapphire substrate 1, the ZnO film and an interdigital transducer electrode 3. By this constitution, the spurious response of the Raileigh wave to the Sezawa wave is reduced.