Method for producing sugar and a useful material

Object of the present invention is to provide a method for producing sugar and ethanol, which can be utilized sugarcane bagasse obtained combustion energy supply almost the whole amount of energy consumed in the manufacturing process of sugar alcohol and the like, without causing sugar yield reduced. The present invention provides a method for producing sugar from sugar cane and a useful substance, characterized by comprising: (a) generating step and bagasse from sugar cane juice, (b) generating step and the sugar juice from the molasses, (c) the juice to steps (a) and (b) obtained, molasses and bagasse as a raw material in the production of useful energy and the stem of sugar cane comprises 15 mass% or more of the fiber content, and per unit area the dry matter yield of 40 tons / ha / year or more, all of the energy from the combustion step bagasse obtained by the above-described manufacturing method described above to obtain the energy required 90% or more.