Provided is a method whereby it is possible to produce an elastic wave device exerting excellent frequency-temperature characteristics. An elastic wave device (1) provided with a piezoelectric substrate (10), an IDT electrode (11) formed on the piezoelectric substrate (10), and a dielectric film (20) formed on the piezoelectric substrate (10) so as to cover the IDT electrode (11) and containing Si and O as the main components is produced. The dielectric film (20) is formed by means of a sputtering method in sputtering gas containing H2O.
