A series arm resonator is connected in series to outer IDTs of an SAW resonator filter so that the resonance frequency of the series arm resonator is is the pass band of the series arm resonator. A parallel arm resonator is connected in parallel to a central IDT of the SAW resonator filter 1 so that the anti-resonance frequency of the parallel arm resonator is in the pass band of the series arm resonator. Thus, VSWR in the pass band is decreased and the amount of attenuation in the rejection band is increased. <IMAGE>
