To securely deaerate gas from a bag body by preventing an air passage from being blocked by stored contents when gas in the bag is deaerated using the exhaust nozzle of a vacuum cleaner, suction mechanism or the like.

Bedding or clothing P is stored into the bag body 1 from its opening 2, and the opening 2 is closed. The exhaust nozzle N of the vacuum cleaner or the suction mechanism is connected to an exhaust valve mechanism Q disposed in an optional area of a side of the bag body 1, and air in the bag body 1 is exhausted and thus the betting or closing P is stored in a compressed condition. The exhaust valve mechanism Q includes a cylindrical body 4 having an air passage R communicating with the inside of the bag body 1, and a supporting plate 5 having an exhaust valve 6 that fits in the cylindrical body 4, is slidable vertically, and controls a flow of air via the air passage R. The exhaust valve mechanism Q has upright plates 7 radially formed around the air passage R in the cylindrical body 4 in order to press the contents of the bag 1 so as to prevent the contents from coming into contact with the air passage R of the cylindrical body 4. Each of the upright plates 7 has a notch 4e near the air passage P, which is on the center side.