Abstract: In a breathing apparatus the chemical cartridge through which respiratory air flows to generate oxygen is divided into a plurality of air treatment chambers (15 to 18) by means of retaining grids. An impact-damping means (21a, 21b) consisting of a multilayer fine wire mesh, which abuts flat against the relevant front cover is located in the external air treatment chambers (15, 18) whilst provided in the middle air treatment chambers (16, 17) is a damping element (24, 25) consisting of a multilayer fine-wire mesh folded in a zigzag fashion, having fold edges running parallel and at a distance from the outer wall of the chemical cartridge (2), one edge thereof running in a zigzag fashion is fixed to a wire grid (26, 27). The damping elements of each adjacent air treatment chambers are not in alignment. Potassium hyperoxide granules (22) for oxygen generation are located in the air treatment chambers.