To provide a waste enclosing structure and its execution method which enables the simple and sure sealing of waste off only by an underground continuous wall regardless of whether a waste disposal area is newly established one or an existing one, or whether it is an appropriate disposal area or an illegal disposal area, and whether a water-unpermeable layer is present or absent below the waster disposal area, or irrespective of its water cut-off performance.

A space is formed by joining end parts and side parts of an underground continuous wall surrounding a waste disposal area 20 with each other. A plurality of continuous wall bodies 22, 24 close at least lower and side areas of the waste disposal area 20, at least one of the continuous wall bodies 22, 24 is formed of an inclined wall 24, and its lower edge is joined with the continuous wall body 22 or 24 opposite thereto in an intersecting manner.