Cellular glass is a new inorganic thermal insulating material with a structure of separate closed cells. The composition is glass, added with foaming agent. It’s foamed by high temperature in foaming furnace, and then cooled down in cooling oven. It well reserves the chemical stability of inorganic glass. As a result, it has the following features: low density, low thermal conductivity, vapor impermeability, no water absorption, incombustibility, protection from mould and rat eating, high mechanical strength but easy to process and able to bear all kinds of chemical erosions except the hydrofluoric acid.