A surface acoustic wave filter including a piezoelectric substrate, IDT electrodes
which are formed on the piezoelectric substrate and are connected to balanced type
terminals. Further, IDT electrodes are formed on the piezoelectric substrate and
are connected to an unbalanced type terminal, connection electrodes of connecting
the IDT electrodes, the IDT electrodes IDT electrodes to the balanced type terminals
or the unbalanced type terminal, and a dielectric thin film formed between the
piezoelectric substrate and the IDT electrodes, the IDT electrodes, the connection electrodes.