In this work yeast cells of Hansenula henriici having beta -glucosidase activity were immobilized into the shell side of Amicon hollow fiber membranes and the continuous hydrolysis of cellubiose has been studied. The kinetic behavior of batch and hollow fiber reactor operated in similar conditions were compared. The experimental results allow for the choice of suitable substrate concentrations in order to obtain higher hydrolytic yield or alternatively higher glucose production rates. An increase in the amount of cells used to load the continuous reactor can produce a reduction in flow conditions which may be negative in long time experiments.