Bacillus circulans VTT-E-87305 was found to be an efficient producer of endo-β-xylanase in alkaline media. The enzyme was induced by xylan. The highest activities, up to 6600 nkat/ml (400 IU/ml) were produced within 2 days. Extracellular β-xylosidase was also produced but the production of side-chain splitting enzymes (α-arabinosidase and acetylxylanesterase) and of cellulase was low. The pH optimum of the overall xylan saccharifying activity was 7.0 and 40% of the maximal activity was expressed at pH 9.0.