To provide a buried conduit pull-box which has a circular aperture, a circular cover and a polygonal main part, can be installed on a wall or a ceiling without necessity of setting an installation direction and facilitates the straight installation of buried conduits.

In order to install a buried conduit pull-box 11, after a plurality of conduits 1 are installed along with the installation of reinforcements, the reinforcement at a predetermined position for the pull-box 11 are cut off by fusion to secure an installation space for the buried conduit pull-box 11. The buried conduit pull-box 11 is installed in the space so as to have the side surfaces of its main part 13 to which the plurality of conduits 1 are connected approximately perpendicular to the axial directions of the respective conduits 1.