To reduce dripping-down of a liquid when executing objective work being work including spray of the liquid to exterior of a building.

A worker carries out the objective work, for example, on a mast climbing type elevation scaffold 110 elevated along the building 1. The elevation scaffold 110 includes a fence 113 surrounding a scaffold board 111. A front fence part 113A faced to the building 1 out of the fence 113 is inclined toward the building 1. The scaffold board 111 and the fence 113 are covered with a water-impervious sheet, and a ship-shaped space is formed by the water-impervious sheet. Water reserved in the ship-shaped space flows to the vicinity of a drainage port 3 of the building 1, by a draining pipe 130. The liquid generated by executing the objective work reaches the ship-shaped space through the front fence part 113A, and is drained from the drainage port 3 via the draining pipe 130.