To obtain a product with no void and no crack and with high quality in a short time and to obtain a flat top face without using a trowel finishing when a secondary product of concrete is to be produced by using a form.

Ready-mixed concrete is dilled into a form main body 6 by adding a vibrational energy. In addition, when volume of the ready mixed concrete in the above described concrete form 6 is shrunk, the ready mixed concrete is dilled again from feeding cylinders 7 provided on a lid plate 8 and air and bleeding water in the form are discharged from a number of vent holes and water passages formed on the lid plate 8 by filling again and after the filling is performed again, pushing rods 9 are inserted into the feeding cylinders 7 and the air and bleeding water in the form main body 6 are discharged again by applying filling pressure.