Patent ID: 8575818

Claim:
A surface acoustic wave element comprising: a piezoelectric substrate; a comb-shaped electrode disposed on the piezoelectric substrate; and an insulating film disposed so as to cover the piezoelectric substrate and the comb-shaped electrode; wherein the piezoelectric substrate, the comb-shaped electrode, and the insulating film are arranged to utilize a Rayleigh wave as a propagation mode of a principal response; the comb-shaped electrode is made of a material including at least one of copper and platinum as a primary component that has a higher density than a material from which the insulating film is made; and 0.01≦h/λ≦0.03 is satisfied, where λ is a wavelength of an elastic wave that propagates in the piezoelectric substrate and h is a difference between a maximum value and a minimum value of a thickness dimension from a top surface of the piezoelectric substrate to a top surface of the insulating film.