Ladder-type surface acoustic wave filter with different apodizations

A surface acoustic wave filter includes a piezoelectric substrate, and at least two series arm resonators 51, 52 and at least one parallel arm resonator P1, P2, P3 each constituted by a one-port surface acoustic wave resonator, disposed on the piezoelectric substrate. The at least two series arm resonators and at least one parallel arm resonator are connected to define a ladder-type circuit. Each of the at least two series arm resonators includes an interdigital transducer weighted by apodization, and the apodizations for the at least two series arm resonators 51, 52 are different from each other.