Ethanol production using glycerol as a carbon source was performed by Enterobacter aerogenes immobilized on calcium alginate beads. To improve the ethanol production, the optimal conditions such as loading amount of immobilized cells and glycerol concentration were investigated. The optimal loading amount of immobilized cells and glycerol concentration were 10 mL of calcium alginate bead and 10 g/L, respectively. Consequently, glycerol consumption rate, ethanol concentration and yield were 0.32 g/$L{cdot}h$, 3.38 g/L and 0.43 g/g on the batch production, respectively. Continuous production of ethanol was successfully achieved using two types of immobilized cell reactors (continuous stirred tank reactor and packed bed reactor) from 10 g/L of glycerol. In the continuous stirred tank reactor, glycerol consumption, ethanol concentration, specific productivity and yield were 9.8 g, 4.67 g/L, 1.17 g/$L{cdot}h$, 0.48 g/g, respectively. The concentration of produced ethanol was 38-44% higher comparison to batch fermentation, and continuous stirred tank reactor showed better performance than packed bed reactor.