To simplify an arranging process of deck members forming the upper face of a deck, and to facilitate replacement repair of broken deck members.

The deck comprises a rectangular frame comprising sleepers 21 and joists 90 orthogonal to the sleepers; a plurality of struts 9 supporting the rectangular frame; a deck base material 22 of approximately C-shaped cross section disposed in a right-angled direction to the axes of the sleepers 21 and fixed to the upper faces of the sleepers 21; the deck members 23 fixed along the upper face of the deck base material 22; and first fixtures 3 for connecting/fixing the sleepers 21 to the deck base material 22. The deck base material 22 is disposed so that an opening edge 221 appears below, and the first fixtures 3 can fix the sleepers 21 and the deck base material 22 and release the fixation through the opening edge 221.