To efficiently perform the multilayer injection of a plurality of kinds of melts.

A multilayer injection molding apparatus has the integrated moving/dividing bush 22 piercing the opening part in a front melt distributing manifold 8 from a rear melt distributing manifold 20 to a centered heating nozzle 10. Each bush 22 is formed by integrating two or three layers and these layers are drilled or processed to form the melt hole connected to the melt conduit between these layers. By this constitution, one melt from the rear melt distributing manifold 20 is divided into several hole parts to pierce up to the annular melt flow path of the centered heating nozzle 10. There is also a mode such that the bush 22 divides the second flow of the melt from the front melt distributing manifold 18 to the other annular flow path in the centered heating nozzle 10.