To make bond of a branch to each molding tool and treatment or the like of piping easy by a method wherein molding of each set of a plurality of sets of cast molding tools is enabled to be independently advanced.

In a piping apparatus for cast molding tool wherein a plurality of branches 33, 35, 37, 38 branched from main pipes 32, 34, 36 are provided, and a corresponding branch can be bonded to each set of a plurality of cast molding tools 22, an on-off valve is provided to midway of each branch 33, 35, 37, 38, and a piping route to the molding tool of each set is enabled to be independent. A plurality of pieces of branches 33, 35, 37, 38 capable of being bonded to respective sets of cast molding tools are assembled per each set of molding tools.