PURPOSE: To surely prevent defect of blow holes, etc., caused by gas generation around a pipe and to efficiently mass-produce the high quality cast products in high yield and low cost in the casting of the aluminum cast product forming pipe line by the cast-in of the aluminum pipe arranging a heat resistant film on the surface.

CONSTITUTION: In the cast-in pipe casting method manufacturing the pipe line 5 of the aluminum cast product M by arranging the aluminum pipe 6 having a heat resistant film 8 on the surface and pouring the molten aluminum the aluminum pipe 6 providing plural small holes 7 penetrated from the inside to the outside on the peripheral surface is used.