A method for reverse-filling cosmetic material having an irreversible property and a cosmetic container filled therewith, including the steps of: sealing the top part of the cosmetic inner container, the top and bottom of which are open, with a filling mold, and turning the cosmetic inner container upside down to reverse-position the cosmetic inner container so that the sealed top part of the cosmetic inner container is directed downward and the open bottom part thereof is directed upward; and filling the cosmetic inner container through the bottom part thereof with the cosmetic material. In so doing, the top surface of the cosmetic material filled in the cosmetic container is smooth without any bumps, moisture seepage phenomenon is prevented, and cosmetic material having excellent applicability can be provided as the hardness thereof is relatively low by reverse-filling the cosmetic container with cosmetic material having an irreversible property, such as agar.