A transversal surface acoustic wave filter includes an input-side
interdigital electrode, an output-side interdigital electrode, and a
shield electrode, which are provided on a surface wave substrate. The
distance between an excitation point of the input-side interdigital
electrode, which is closest to the shield electrode, and an intermediate
point between the shield electrode-side end of the input-side
interdigital electrode and the input-side interdigital electrode-side end
of the shield electrode is in the range of about 0.8.lamda. to about
0.975.lamda., wherein .lamda. is the wavelength of a surface wave.