Magnons are Bose particles, therefore under particular conditions they should demonstrate Bose-Einstein condensation. However, to reach BEC at room temperature one needs to increase the chemical potential of the magnon gas above the zero value characterizing the state of true thermal equilibrium. In this lecture I present our recent results on BEC in magnons gas, driven by a microwave pumping. The room temperature kinetics and thermodynamics of the magnons gas was investigated by means of the Brillouin light scattering technique. We show that for high enough pumping powers the relaxation of the driven gas results in a quasi-equilibrium state described by the Bose-Einstein statistics with a non-zero chemical potential. Further increase of the pumping power causes BEC in the magnon gas documented by an observation of the magnon accumulation at the lowest energy level. Using the sensitivity of the Brillouin light scattering to the coherence degree of the scattering magnons we confirm spontaneous emergence of coherence of the magnons accumulated at the bottom of the spectrum, if their density exceeds a critical value. Interference of two magnon condensates is observed as well.