Abstract: Method and device for handling a carbon dioxideabsorbing compound in anaesthetic systems of the circle system type. The anaesthetic system is arranged with an openable container (10) arranged for gas passage in such a way that air mixed with carbon dioxide from the patient who is to be connected to the system, passes through the container in order to be returned to the patient. According to the invention, a quantity of carbon dioxide-absorbing compound (16) is provided with a gas permeable cover (17). The unit, intended for carbon dioxide absorption, designed in this way is placed inside the container (10). When it is considered to be consumed, it is removed from the container and replaced with a new one.