An elastic wave element includes a piezoelectric substrate, an interdigital electrode provided on the piezoelectric substrate, a silicon oxide film covering the interdigital electrode, and a silicon nitride oxide film provided on the silicon oxide film. A film thickness H of the silicon oxide film and a wave length λ of an elastic wave propagating through the piezoelectric substrate satisfies a relation of H/λ≧0.15. The elastic wave element reduces fluctuation of propagation characteristics of elastic waves, and has high reliability.