The gas analyser has a first measurement cuvette (4) which can be filled with the measurement gas (9) and through which an infrared measurement beam (3) can be passed. A radiation transmissive detector device (5) arranged after the first cuvette has an optopneumatic detector contg. carbon dioxide and/or an optopneumatic detector contg. carbon monoxide . A second measurement cuvette (6) arranged after the detector device (7,8,10,11) can be filled with the measurement gas and has attached detector for hydrocarbons and nitrogen oxide.
