PURPOSE: To produce a product having a smooth surface and high strength and to shorten an ageing time by a method wherein ready-mixed concrete is charged in a form to be stirred and the form is evacuated to discharge air and a part of excessive moisture before the concrete is pressed and compressed to discharge excessive moisture.

CONSTITUTION: In producing a concrete block by molding ready-mixed concrete 2 by using a form 1 made free to internally pressurize and evacuate, in the first place, the ready-mixed concrete 2 is charged in the steam form 1 having an opening part provided to the upper surface thereof and a lid 7 is applied to the opening part and, in the second place, air is discharged from the upper part of the form 1 while the form 1 is pressurized from the bottom part thereof and the ready-mixed concrete 2 is stirred. In the third place, the air in the form 1 is sucked under vacuum to reduce the pressure in the form 1 to discharge the air and a part of excessive moisture present in the ready-mixed concrete 2 to the outside of the form 1 and, in the fourth place, the ready-mixed concrete 2 is compressed by pressurizing the form 1 from the upper part thereof to discharge excessive moisture from the small hole 14a provided to the bottom part of the form 1.