UNDERGROUND BOX HAVING SUPPORTING MEMBER

PROBLEM TO BE SOLVED: To prevent the body of an underground box from being transformed or broken by the load working on a cover member by providing a supporting member to attach a cover-mounting member with an installation part to the bottom of a hole for burying. SOLUTION: A pole part 10 is provided with a bottom level adjusting mechanism 7a for performing the level adjustment of a supporting member B, and this is an installation part 7 for the time of installing the body A of an underground box in a bored hole 11 for burying. The bottom level adjusting mechanism 7a is composed of a flange part 10a, a bottom bolt member 13 to be inserted into an insertion hole 12, and a bottom plate member 14. The bottom member 14 is a member for dispersing the load of an underground box or the load of a vehicle or the like, transmitted via a cover member 2, and this prevents the sink of the body 1 of the underground box. As a result, the external force working on a box member can be broken of being transmitted to the body A of the underground box, and inconvenience such as a body A of the underground box being transformed excessively or that breaking, etc., can be avoided.