An acoustic wave device and an electronic component are disclosed. The acoustic wave device includes a substrate, excitation electrodes on the substrate and a cover. The cover comprises a frame member on the substrate, and a lid member. The frame member surrounds the excitation electrodes and includes an inner wall, top surface and an outer wall. The lid member is disposed on the top surface, and includes first and second surfaces opposite to each other, and a descending part on the second surface. The second surface faces the substrate. The descending part extends downward from the second surface, and covers at least a part of the inner wall or at least a part of the outer wall. The electronic component includes the acoustic wave device on a mounting substrate via an electrically conductive bonding member, and molding resin covering the device.