A cosmetic case having a first cover for a main body and a second cover for a refill container which is inserted in a container of the main body is provided. The second cover has an air vent structure for preventing a volatile agent, which is contained in an oily and solid foundation, from volatilizing. The air vent structure of the second cover blocks the discharge of the air inside the refill container so as to prevent materials of the beauty product from ventilating when the first cover for the main body is closed after closing the second cover for the refill container. Sealing by the second cover is maintained as well as easier operation of closing because ventilation is performed by a valve provided in the second cover.