PURPOSE: To improve an attenuation characteristic outside band by connecting a parallel circuit consisting of an inductor and a resistor between the stages of lateral coupling multiplex mode SAW filters of multistage cascade connection.

CONSTITUTION: A SAW filter in which SAW resonators 12, 13 are comprised by providing with reflector electrodes 12b, 12c before and behind the propagating direction of the surface waves of at least one or more IDT electrodes 12a, 13a provided on a piezoelectric substrate 1, and the lateral coupling multiplex mode SAW filters 2, 3 are comprised by arranging the SAW resonators 12, 13 at least in two or more directions intersecting orthogonally to the propagating direction and also adjacently and in parallel, and the lateral coupling multiplex mode SAW filters 2, 3 are multistage cascade connected via the inductor 4 of parallel connection is the one in which a resistor 5 is connected in parallel with at least one of the inductors 4.