Abstract: The invention relates to biotechnology, in particular to methods and means of physical action on biological structures of photosynthesing microorganisms, phototrophic algae in particular. The invention can be used in pharmaceutical, cosmetic and foodstuff industries, as well as for obtaining biofuel from algae In the process of the method implementation radiation of cultivated solution of photosynthesizing microorganisms/phototrophical algae is carried out by the action of electromagnetic waves of mm range and low intensity. Stimulation of increasing photosynthesizing microorganisms/phototrophical algae biomass and biomass of their pigments (excretions) is obtained with industrial production as a result of the resonance effect which is caused by the interaction of electromagnetic wave and biological cell.