Signal direct wave hardly propagates to the output terminal, it is possible to increase the out-of-band attenuation, to provide an elastic wave filter.
Acoustic wave filter 1 includes a piezoelectric substrate 2, an IDT electrode provided on the piezoelectric substrate 2, a first shield electrode 6a provided on the piezoelectric substrate 2, leading to the first shield electrode 6a a first insulating film 5a which is laminated on the piezoelectric substrate 2 as a first signal terminal 4 is provided on the first insulating film 5a, the second is provided on the piezoelectric substrate 2 of comprising a signal terminal 3 is provided on the piezoelectric substrate 2, and a first ground terminal 7a connected to the ground potential. The first shield electrode 6a is, IDT electrodes and first, not electrically connected to the second signal terminal 4,3. In plan view, the first signal terminal 4 is contained in the first shield electrode 6a. One of the first signal terminal 4 and the second signal terminal 3 is an output terminal, and the other input terminal.