PURPOSE: To secure size precision and improve productivity by integrally constituting the longitudinal terminal frame body of a main frame with a protruded junction body connecting a side frame body, connection bodies, and a support body mounted on a building beam.

CONSTITUTION: In a main frame 7 structure constituted of a footstep connected and moved endlessly, a mobile handrail, a parapet, a driving equipment, multiple side frame bodies 7B, and a terminal frame body 7A forming both terminals of the side frame bodies 7B, a protruded junction body 7a to connect the side frame bodies 7B is fitted to the terminal frame body 7A in advance. Connection bodies 7b and 7c to connect the side frame bodies 7B together and a support body 7d protruded and mounted on the building beam F side are arranged into an integrated structure. The terminal frame body 7A is made sturdy, it is utilized as a kind of a gauge, and the side frame bodies are correctly assembled.