To provide a stable lubricative performance for a guide hole of a cast product.

A producing method of a cast product having a guide hole includes a process where solid lubricator 2 is set into a forming die of a shell core 3 for the guide hole and the solid lubricator 2 is fixed by the shell core 3 at the same time of forming, a process where the shell core 3 is held with a lost form assist pattern 4 and this shell core is assembled in the guide hole part of the lost foam pattern 5, and a process where the solid lubricator 2 is inserted into the guide hole of the cast product by pouring molten metal into a sand mold burying the lost foam pattern 5, to form the guide hole exposing the solid lubricator 2 inserted in the cast product.