Because xylanase is one of the few hemicellulolytic enzymes able to hydrolyze xylan, it is now widely used in industry. Due to rising usage in pulp and paper, animal feed, food and beverages, textile and biofuel sectors, xylanase manufacturing has improved greatly. Under conditions of submergency or solid-state cultures, large-scale fermentation depends on filamentous fungi (e.g., Aspergillus spp.) and bacteria (e.g., Bacillus spp.). Enhancements in the yield and stability of xylanases have resulted from improvements in fermentation conditions, better use of substrates (for example, agro-industrial materials) and changes in the DNA of microbial strains. Processes developed downstream have been improved to allow for economical enzyme recovery and formulation. In addition, new trends in bioprocess monitoring, bioreactor development and scale-up methods make it easier to produce xylanase sustainably. This chapter explains how industrial xylanase production has developed and what challenges remain, also providing directions for better and more extensive use in the future.