To provide an easier tool, a special flange and a flange space extending method in view of problems of a working space, a place, or the like and extremely troublesome work which takes time to uniformly extend a space between flanges using a conventional tool because members such as a valve and a flowmeter are mounted between the flanges in a distribution line and the flange space was pushed open using a chill hole, a jack, or the like between two flanges to remove these members.

This flange space extending tool comprising a threaded extension bolt 2, a flange opening fitting 5a provided with a threaded through-hole 3 screwed with the extension bolt, and a hole 4b for receiving the tip part of the extension bolt, is provided as a tool for extending the flange space by fixing the fitting to a flange outer peripheral part 1.