PURPOSE: To make it possible to easily build up a gangway in a site to mount it to an exterior wall of a building and to facilitate the conveyance of the built-up gangway.

CONSTITUTION: Both right and left side pipes 1 and 1 are constituted of gangway build-up bodies 3 fitting both ends of each of step bars 2 to projected pieces 6 and 6 to the opposed surfaces to connect, handrails 5 fitting both ends of each of the step bars 2 to the projected pieces 6 and 6 to the opposed surfaces or connecting them with bolts, and joints 4 fitting the gangway build-up bodies 3 to each other or the gangway build-up bodies 3 to the handrails 5 to connect. Stays 12 fixed to an exterior wall of a building with bolts are provided to gangway build-up bodies 3 or handrails 5, etc.