A new alkaline phosphatase was obtained as homogeneous preparation from culture filtrate of the spore-forming Bacillus intermedius. B. intermedius phosphatase was shown to be monomer with molecular weight of 47 kDa. The enzyme possesses phosphomonoesterase and phosphodiesterase activities and exhibits a broad specificity towards a wide variety of substrates. The purified phosphatase had an optimum temperature of 50 degrees C, optimum pH of 9.5 and was stable until 60 degrees C at pH 8-10. The effect of divalent metal ions and thiol reagents on catalytic activity of the enzyme was studied.