Bulk elastic wave filter device

Provided is a bulk elastic wave filter device having a good heat dissipation property. The bulk elastic wave filter device comprises: an acoustic multilayer film that includes, on a supporting substrate, a first layer and a second layer layered in an alternating pattern, the first layer having a prescribed characteristic acoustic impedance, the second layer having a lower characteristic acoustic impedance than the first layer; and an active element that is provided on the opposite side of the acoustic multilayer film from the supporting substrate. The active element includes a first electrode layer provided on the acoustic multilayer film, a piezoelectric layer provided on the first electrode layer, and a second electrode layer provided on the piezoelectric layer. A portion of or the entirety of the acoustic multilayer film has electrical conductivity. An insulating layer is provided between the acoustic multilayer film and the first electrode layer. In a preferable configuration example, the second layer, wh