The invention provides a waterproof top end stop for a slide fastener for enhancing its waterproof and airproof properties, wherein fastener elements are attached to opposing side edges of a pair of waterproof fastener tapes, an elastic top end stop is attached adjacent to the fastener elements and includes an accommodating portion in a center for accommodating a diamond; protrusions projecting ina front/rear surface direction around the accommodating portion and making a pressure contact with inner faces of blades; passage portions at entrances of the top end stop; and pressing portions on outer edges of insertion leg portions of the top end stop corresponding to the passage portions, outer sides of the pressing portions project outward with respect to contact faces of leg portions of anadjacent fastener element, and the pressing portions are pressed by flanges of the slider and the passage portions are closed firmly simultaneously.