The invention relates to a thermo-photo-bioreactor and to a method for the culture and mass micropropagation of Deschampsia antarctica in vitro. The invention comprises a discontinuous immersion reactor for biomass micropropagation, including means for incorporating chemical inducing agents (salt, metals, organic compounds, etc.) and internal luminescence or illumination means (UV radiation and temperature) for supplying said chemical inducers and/or illumination during any growth phase of the vegetable or plant material (multiplication or propagation and/or maintenance). The invention is advantageous in that it can be used to produce large quantities of biomass of the aforementioned Antarctic species, while providing conditions suitable for said plant to produce metabolites that can be used for human health and personal care.