Abstract: A manual respirator apparatus for connection to an inhalation line connected between an automatic respirator and a patient and usable with a breathing gas supply under pressure, comprises, a block housing having a breathing gas supply inlet connected to the breathing gas supply, an inhalation line connectable to the inhalation line and an inhalation line outlet connectable to the patient and an exhalation inlet connected from the patient to the block housing. The block housing has a pressure chamber therein and is connected to an elastic breathing gas bag. A connection housing in the passage between the inlet from the gas supply line to the pressure chamber has adjusting valve means in the pressure chamber responsive to the pressure therein and to the fluctuation of the elastic breathing gas bag to permit flow of respirator gas through the connecting passage.