To provide a drain hole of a structure for drainage which is excellent in drainability of infiltrating water, such as rain water, infiltrating a drainage functional layer of a drainable pavement on the top and side surfaces of the drain hole, and excellent in drainability of surface water such as rain water when the upper surface of the drain hole is exposed to a road surface.

A drain hole 5 is provided in a horizontal member 6, which faces a water passage 4 provided below culvert type or gate type blocks, lids and the like, to communicate the top surface 6a of the horizontal member 6 with the water passage 4. A recessed part 5a depressed from the top surface 6a is provided on the top surface 6a with a predetermined width and a proper length. A hole part 5e, which communicates with the water passage 4, is opened in the bottom surface 5d of a water collecting part 5c formed by further depressing the inside bottom surface so that the edge bottom surface along the lengthwise direction of the recessed part 5a forms a step part 5b. Both edges along the lengthwise direction of a plate-like water permeable lid 5f, which is upward projecting-curved or bent in the width direction, are supported by the step part 5b or an inside wall surface 5j continued to the upper side of the step part 5b to be fitted into the recessed part 5a. When the top surface 6a of the horizontal member 6 faces a drainage functional layer 7a of a drainable pavement 7, the water permeable lid 5f is brought into contact with the drainage functional layer 7a.