PURPOSE: To perform simultaneous interconnection of a pair and a plurality of pipings by a method wherein a moving body in a moving body cell and a fixed piping header are positioned facing each other and a connection part between the moving bodies is connected to the other piping group.

CONSTITUTION: A moving body cell of which a unit B connected to a piping group 4 consists crosses a fixed piping header 5 at right angles at intervals of a piping distance of the fixed piping header 5 of the unit A of a piping group 3 and arranged in parallel to each other, whereby a moving body 8 moved through the moving body cell is positioned facing the fixed piping header 5, and respective built-in fittings 6 and 9 are connected to each other. Since the other ends of the moving bodies 8 are connected to the respective piping groups B through a flexible piping 10, connection between a piping group A and a piping group B each having a plurality of fixed piping header 5 is practicable. Thus, interconnection of a pair and a plurality of piping groups is simultaneously practicable, resulting in the increase of the speed of production and facilitation of management of tanks.