Abstract: The invention concerns a device for hermetically and safely closing a feeding bottle to avoid any leakage of the liquid. Said closing device comprises: a rotary closure consisting of an inner ferrule and of an outer ferrule each having an offset opening respectively and, the inner ferrule being lodged in the outer ferrule. An internal thread of the inner ferrule enables the rotary closure to be fixed to the threaded neck of the feeding bottle. A nipple, inserted in a retaining ring comprising an internal thread, is fixed to the threaded neck of the rotary closure. A cap is provided, which enables the nipple to be protected. The inventive device is particularly designed for hermetically closing the feeding bottle.