Abstract: A supporting device for a multiplicity of parallel, highly elongate bioreactor elements having an at least partially transparent wall of plastic, through which a microorganism-inoculated nutrient solution is conducted for producing biomass by photosynthesis, includes a plurality of stationary support pylons disposed along the bioreactor elements and horizontally spaced apart from one another. The expenditure on production and assembly is decreased by providing at least one carrying element running between at least two support pylons above the respective bioreactor elements to be carried. The carrying element is supported on the corresponding support pylons and the bioreactor elements to be carried are connected to at least one carrying element by at least one holding element at least at one support point situated between the two support pylons.