PURPOSE: To make inserted loss small, to make out-of-passing band attenuation characteristic large and to facilitate matching by dividing the interdigital transducers(IDT) of two SAW resonators into three pieces and connecting them so as to prevent electrostatic coupling.

CONSTITUTION: Conductors for forming two reflectors in the two SAW resonators are mutually connected with the interdigital electrode conductor on a side not connected to the input/output terminals 105 and 106 of a second IDT by connection conductors 122.125 and 120.119 and are grounded to a ground potential by 101, 103 and 102, 104 in the reflectors. In first and third IDTs, the interdigital electrodes on the side to be grounted to the ground potential are mutually connected by ground side connection conductors 123, 124 and 121, 118 and connection is performed by the conductors for electrostatically separating first and second SAW resonators. Thus, the electrostatic coupling between the second IDT and first and third IDTs can be eliminated and the electrostatic coupling between the two first IDTs provided on the first and second SAW resonators can be also eliminated.