When pressing kneaded sand in a kneading sand tank into a mold by a pressing member, a pressing force applied to a kneaded sand layer in the kneading sand tank is monitored and a moving position of the pressing member is monitored from when the pressing member starts to move. A pressing start time at which the kneaded sand starts to flow into the mold is identified based on the pressing force applied to the kneaded sand layer in the kneading sand tank, and a pressing starting position of the pressing member at the pressing start time is identified. As a result, the pressing start time and the pressing starting position of the pressing member when the kneaded sand starts to flow into the mold are accurately identified, so the reliability of a filling evaluation of the kneaded sand into the mold is improved.