A plurality of surface acoustic wave resonators including a comb electrode
and a grating reflector are coupled on a piezoelectric substrate.
Dielectric film is formed on the surface of at least one surface acoustic
wave resonator. No dielectric film is formed on the surface of at least
one other surface acoustic wave resonator. Thus, a SAW filter where the
insertion loss into a pass band is small, the steepness is sufficient,
and the band is wide can be obtained.