This invention relates to a three-dimensionally constructed net A for use in various applications including a water collecting and discharging net or a protection net in the faces of slopes in created land or residential sites, a plant protection net, such as a spray sowing net and so on, a building protecting net, an agricultural light-shielding net and a medical net. The net may be conveniently formed by knitting or weaving, so that cord portions which define the meshes are made in hollow three-dimensional construction capable of ventilation and water passage. Thereby, despite the fact that the net is a thick, three-dimensional body, the possession of a void content by the cord portions improves the ventilating and water collecting and discharging effects and saves weight, facilitating the handling and installing of the net, so that the net can be easily handled and well suited for the above-mentioned applications.