A novel fungus belongs to the genus Trichoderma whose cellulase can be used to hydrolyze cellulose-based biomass without degradation of xylan contained in the biomass into xylose, and a method produces glucose and xylo-oligosaccharides from a cellulose containing biomass using it. The fungus belonging to the genus Trichoderma includes N- and C-terminal domains of the β-xylosidase 1 (BXL1) gene, but lacks the Fn3-like domain of the gene due to its disruption. The use of this fungus belonging to the genus Trichoderma results in deletion of β-xylosidase activity and increase in β-glucosidase activity. Thus, in hydrolysis of cellulose contained in biomass, xylan contained in the biomass is not degraded into xylose, which enables efficient production of glucose and xylo-oligosaccharides.