An elastic wave resonator including comb-shaped electrodes and reflector electrodes formed on a piezoelectric substrate. In one example, an overlapping portion between the comb-shaped electrodes includes a first overlapping region and second overlapping regions. The second overlapping regions can be provided on both outside edges of the first overlapping region. In one example, the overlapping width of the first overlapping region is greater than the overlapping width of the second overlapping region, and the electrode finger pitch in the second overlapping region is greater than the electrode finger pitch in the first overlapping region.