Elastic wave filter

An elastic wave filter, comprising:

• electrode fingers;
• a first busbar and a second busbar;
• and
• inclined electrode portions each having a narrower distance between the electrode fingers from the first busbar toward the second busbar, wherein
• the inclined electrode portions are constituted as an input-side IDT electrode portion and an output-side IDT electrode portion, the input-side IDT electrode portion and the output-side IDT electrode portion being separated from one another in a propagation direction of an elastic wave,
• the elastic wave filter includes a dummy electrode disposed in at least one of the input-side IDT electrode portion and the output-side IDT electrode portion to suppress reflection of a diffracted elastic wave by the busbar and to suppress spurious response at an end portion in a frequency pass-band,
• the dummy electrode is disposed between a distal end of the electrode fingers and another busbar, the electrode fingers extending from one busbar among the first busbar and the second busbar, the dummy electrode being disposed separately from the distal end, the dummy electrode extending from the other busbar, and
• the dummy electrode has a width dimension and a pitch that are determined such that none of a period shorter than a shortest period of the electrode fingers and a period longer than a longest period of the electrode fingers is satisfied.