PURPOSE: To provide a casting method for a bent pipe which can surely and easily cast the bent pipe having the prescribed shape in short time without shrinkage cavity without using the useless material in more than the necessary material as the product.

CONSTITUTION: This method is composed of a first process, in which molten metal is cast into a mold having a molten metal pouring cavity in almost uniform thickness to the whole body and uniformly cooled and solidified over the whole body of the molten metal to obtain an intermediate product 1, and a second process, in which hot isostatic pressurizing treatment is applied to the above intermediate product 1.