A first main plate has a first principal surface and a second principal surface. A second main plate has a third principal surface, a fourth principal surface, and an aperture. A piezoelectric element is provided on the first main plate and vibrates the first main plate. A first frame is disposed outside an outer peripheral end of the first main plate. First connecting portions connect the first main plate and the first frame to each other. Apertures are formed between the first connecting portions and connect a space adjacent to the first principal surface and a space adjacent to the second principal surface to each other. The second frame is disposed outside an outer peripheral end of the first frame. A second connecting portion connects the first frame and the second frame to each other.