A SAW filter comprises an IDT disposed on a piezo-electric substrate,
wherein the IDT includes comb-shaped electrodes having a plurality of
interdigital electrodes arranged in a propagation direction of surface
acoustic waves and bus bars for connecting these interdigital electrodes,
arranged in opposition, and the interdigital electrodes are crossed with
one another. The IDT comprises one or more branch electrodes branched
from the interdigital electrode and positioned in a non-overlap zone
between an overlap zone at which the interdigital electrodes overlap and
the bus bar, and the branch electrode includes a branch electrode body
extending in a direction substantially orthogonal to the propagation
direction of surface acoustic wave. The SAW filter can be applied to any
of a longitudinally coupled multi-mode filter, a ladder type filter, a
resonator, a filter having a resonator connected in series to a
longitudinally coupled multi-mode filter, and the like. A SAW filter and
a SAW resonator highly resistant to damages to the electrodes with high Q
and low insertion loss can be provided.