This invention belongs to the field of porous silicate foamed materials production, namely, production of foamed glass-ceramic blocks which may be used in building, radio engineering, metallurgy, shipbuilding, chemical, medical industries and agriculture. The technical result is manufacturing of foamed ceramic materials with thickness up to 200 mm with uniformly closed finely porous structure over the whole material volume and high physicochemical properties. The method of large-size glass-ceramic foamed blocks fabrication includes preparation of finely ground glass-ceramic phase with particle size of 1 to 50 μm containing production waste with silicon carbide content of at least 10 weight %. Then a finely ground batch is prepared with particle size of 1 to 50 μm for foamed blocks fabrication containing finely ground glass-ceramic phase in quantity of 5 to 95 weight % and binding component as a remainder, subsequent drying and pressing thereof to obtain blanks with thickness of 15 to 60 mm in the form of large-size tiles, and drying of large-size tiles to residual moisture content of 0.5 %. Then large-size tiles are fed to kiln by roller conveyor without moulds and trays application. Roller conveyor speed in the end of large-scale tiles sintering zone of kiln is lower by 5 to 25% than before this zone, which ensures formation of uniform sintered bar with subsequent foaming thereof. Prior to feeding of dried large-size tiles to kiln their lower surface and two side surfaces parallel to roller conveyor movement are covered with double-layered engobe, and after foaming in the end of kiln the bar is cooled rapidly to the temperature providing bar shape stability, and a notch is applied on its surface perpendicularly to roller conveyor movement movement. After bar removal from kiln it is separated into blocks along notched lines, then blocks are fed to annealing furnace and then to mechanical treatment.