PURPOSE: To shorten working time as a result of parallel execution of die closing process and pressurizing process and to improve working efficiency by starting to pressurize molten metal together with starting the die closing and reaching to the first prescribed pressure till completion of the die closing.

CONSTITUTION: The molten metal is started to pressurize together with starting the die closing so as to reach to the first prescribed pressure till completing the die closing. By this method, as the result of parallel execution of the die closing process and the pressurizing process, the operating time is shortened. Further, in the low pressure casting method, in which the die is closed and the molten metal is poured into cavity in the die under pressurizing and the die is opened after pouring the molten metal and a casting product is taken out, after completing the above pressurizing, the pressure is reduced until the remained pressure becomes zero, and after that, again this is pressurized to the second prescribed pressure and in this prescribed pressure, the above die is started to open. By this method, the molten metal returned back to a holding furnace easily becomes laminar stream and the molten metal surface is quiet and difficult to be oxidized.