To provide a means of producing a casting with a hollow part formed of a smooth wall part without increasing an environmental load in a production process.

In the method of producing a hollow casting, after casting and molding by pouring molten metal into a mold, treatment for removing the remainder on the surface of a wall part forming the hollow part and treatment for smoothening the surface of the wall part forming the hollow part are simultaneously performed preferably by pouring a smoothening material into the hollow part and swinging the casting.