Abstract: A cover for underground structures, its cover body, and its frame designed to quickly discharge accumulations of rainwater and dirt so as to prevent slipping and skidding from increasing due to these accumulations. The cover body has a multiplicity of patterns of projections and depressions on its surface, one projection independent of another, so that the upper surface of each projection is on about the same level as that of the frame with the depressions formed to surround each of these depressions. The depressions are constructed to become gradually deeper from the central part of the cover body toward the periphery, while the frame also has depressions set up on part or all of its upper surface in a circumferential direction with discharge guides sloping up toward the outer periphery of the frame. The cover for underground structures is made up of a set of the cover body and the frame.