To manufacture a manifold having a desirable shaped runner highly precisely and inexpensively without applying complicated machining.

A first gate member 10, second gate member 12 and nozzle touch member 14 in which through-holes are formed are produced by a precision casting method. The nozzle touch member 14, first gate member 10 and second gate member 12 are joined so that the through-holes mutually communicate by a liquid phase diffusion joining method. After positioning a formed body 24 composed of three members 10, 12, 14 having a runner 26 constituted of three through-holes mutually communicated in a box, the manifold 34 inserted with metal 43 as cast-in is manufactured by casting the molten metal in the box.