PURPOSE: To enable up and down traveling passengers to be simultaneously transported by a single set of escalator by combining an ascending part with a descending part in a forward path of the single set of escalator and forming this forward path into a closed loop of circumference or the like eliminating a return path.

CONSTITUTION: A chain conveyer 1 is constituted in an endless state of chain links 1a and joint links 1b, but a main spindle 2 is pivotally mounted with a fixed space in place of a shaft. The main spindle 2 is inserted turnably penetrating through both side surfaces of a tread surface bed 3 having a tread surface 3a in the upper surface and kickup surfaces 3b in front and rear surfaces in a running direction of the chain conveyer 1. A roller supporting arm 5 is secured to both the side surfaces of the road surface bed 3, securing a shaft 7 pivotally mounting an ascending roller 6 and a shaft 9 pivotally mounting a descending roller 8, in the point ends. An ascending guide roller 11 rolling the roller 6 and a descending guide roller 12 rolling the roller 8 are provided along a running path of the chain conveyer 1. A hand rail is provided in the upper of both the side surfaces of the road surface bed 3.