PURPOSE: To enable a stable supply of a fixed quantity of cement mortal within a mold of a molding device, and a standardization of weight and a thickness of a cement mortal molded product, by a method wherein an air injection port is opened in an inner wall surface of a quantitative measure and the same is connected with a high pressure air generating device.

CONSTITUTION: After blockade of a lower opening part of a quantitative measure 3 by extruding a lower shutter 5 along with opening of an upper opening part of the quantitative measure 3 by pulling an upper shutter 4, cement mortal 2 within a raw material vessel 1 is supplied within a supplying joining cylinder 3A and the quantitative measure 3 by turning a rotary blade 1f. Then the upper opening part of the quantitative measure 3 is closed by the upper shutter 4, the lower opening part of the quantitative measure 3 is opened by pulling the lower shutter 5 and the cement mortal 2 within the quantitative measure 3 is supplied to a mold of a molding device. Air is injected through an injection port 3c by opening a valve 10 by a control part 11, the cement mortal 2 stuck to the inner wall surface of the quantitative measure 3 is dropped wholly by peeling off from the wall surface an supplied to the mold of the molding device.