A respirator shall be improved concerning better utilization of the carbon dioxide absorber (3). To accomplish the object, a transponder (5), which contains data on the type of absorber, the period of use and the current state of consumption, is arranged at the carbon dioxide absorber (3). A transponder polling device (8) at the respirator (1) reads the data from the memory chip (6) and an updated state of consumption is calculated from data on the operation of the respirator and stored again in the memory chip (6).