A microorganism belonging to the genus Gluconobacter oxydans or Acetobacter xylinam, having D-arabitol dehydrogenase activity and D-xylulose reductase (xylitol dehydrogenase) activity, and having the capability of converting D-arabitol to xylitol is allowed to act on D-arabitol in a reaction solution containing a carbon source to produce xylitol.
