This Resuscitator with PEEP-valve adapter can support the artificial respiration and heart-lung-reanimation. The resuscitator can be used to ventilate a patient with breathing arrest as well as to maintain the own respiration of the patient and / or to supply additional oxygen. There are different types for adults, children and infants. To meet requirements of different body heights, the compression frequency can be adjusted and a bag in a suitable size can be chosen.