The present invention relates to a novel xylanase homologous with an enzyme corresponding to a glycoside hydrolase family 10 (GH10) domain and comprising a carbohydrate-binding module family 2 (cellulose-binding module family 2, CBM2) domain, a substrate-binding module, which were isolated from Streptomyces sp. strain HY-14. Particularly, the maximum enzyme activity continues at at least 80% at a pH between 5.0 and 7.5 and the sugar substrates including xylans are significantly degraded in the xylanase, and thus the xylanase can be used as an enzyme in various industrial sectors such as food, feed, and other industries.