A speaker includes a diaphragm, a frame accommodating the diaphragm and an edge attached to an outer periphery of the diaphragm as well as to an inner periphery of the frame so as to retain the diaphragm within an interior of the frame. The edge has a thickness which is smallest at substantially a central portion between the diaphragm and the frame and the vicinity thereof, and increases toward the diaphragm and the frame.