The present paper contains a review of literature data on sources of singlet oxygen in lower atmosphere and methods of its registration. Singlet oxygen gas analyzer developed in OPTEC JSC (St Petersburg, Russia), which operation principle is based on the 9,10-definilantracene chemiluminescent reaction is described in the present paper. The new gas analyzer used for solving a wide range of fundamental and applied problems connected with the processes and phenomena at the boundary between biogenic and abiogenic nature. Its capabilities demonstrated on the examples for monitoring pollutant concentrations in atmospheric air, on the experiments in vivo and in vitro on recording singlet oxygen on the surface of snow and near plants infected by pathogenic fungus, as well as on tests of photocatalytic materials developed for use in medicine and in protection of architectural and sculptural monuments from biodeterioration.