This outdoor structure, which is installed outdoors, such as a bench, a fence, or a wooden path, includes a plurality of metal support posts each including one or more rectangular through holes and arrayed at least in one row in a first direction; and a wooden slat laid across the through holes of the plurality of support posts, in which a cross section of each of the through holes in the first direction includes tapered portions which are narrow at an approximately center portion and become wider toward outside.