An acoustic wave device includes: a piezoelectric substrate; a comb-shaped electrode located on the piezoelectric substrate; a wiring layer located on the piezoelectric substrate and electrically connected with the comb-shaped electrode; a first insulating film located on the piezoelectric substrate, the first insulating film covering the comb-shaped electrode, having an aperture on the wiring layer, and being thicker than the comb-shaped electrode; a second insulating film covering an upper surface of the first insulating film and at least a part of a side surface of the first insulating film in the aperture and having a higher moisture resistance than the first insulating film; and a pad being in contact with the wiring layer exposed by the aperture.