An elastic wave filter including a substrate, a signal line disposed on the substrate and connecting a first signal terminal to a second signal terminal, a plurality of series resonators connected to the signal line in series, and a plurality of parallel resonators connected to the signal line. At least one of the series resonator having an anti-resonant frequency closest to the passband of the filter among the plurality of series resonators, and/or the parallel resonator having a resonant frequency closest to the passband of the filter among the plurality of parallel resonators, is covered with a dielectric film that is relatively thicker than a dielectric film covering the other series and/or parallel resonators.