PURPOSE: To conduct the construction work efficiently by a small-sized simple movable bench when the foundation and pier of a road bridge installed to a mountain section are built without constructing a road for construction by using the spanworm type movable bench.

CONSTITUTION: Movable benchs, which can be forwarded movably in a spanworm type, are divided into ones for the foundation and piers of a bridge and installed at positions along the line of the construction execution of the bridge. Heavy machinery for constructing the foundation are loaded on the movable bench A for the foundation, and the foundation (a) is built near a ground surface. Suspended forms 80 for constructing the piers are mounted to the movable bench B for the piers, and the bench (that is, the suspended forms 80) is elevated by a lifting gear 70B, thus building the piers (b). When these construction processes are completed, the movable benchs A and B are transferred separately to foundation-pier constructing positions in the next rank respectively. The bench A is miniaturized and simplified and can be built at a low position, and a special lifting gear for lifting the forms is unnecessitated in the bench B.