Abstract: A fixed bottle cover device of compressed air thermos bottle comprised a bottle cover having a stationary shaft, on its side edge, which is attached to a holding fixture generally provided in the upper side of the conventional thermos bottle body. The holding fixture includes an external clamp plate and an internal seat plate and between the said two members a coil compressed spring is equipped for controlling the disclosure and closure of the holding fixture so as to be arbitrarily united or severed the bottle cover and the thermos bottle body.