A microreactor was employed for the oxidative dehydrogenation of propane to propylene in order to suppress a deep oxidation of the resultant propylene to CO and CO2. Magnesium ortho-vanadate, doped and undoped with palladium, and calcium hydroxyapatite, were used as catalysts while the reaction temperature was controlled by steady- and unsteady-state conditions. The enhancement of the selectivity to propylene was the most advantageous effect from using the microreactor, and it occurred when calcium hydroxyapatite was used under an unsteady-state. For example, the selectivity to propylene was 0 and 73.0% using a fixed-bed continuous- flow reactor and the microreactor, respectively, under almost identical propane conversion of 3.1 and 3.2%, respectively. The advantageous effect was also achieved, although to a lesser degree, when magnesium ortho-vanadate was used undoped with palladium under both steady- and unsteady-state conditions. However these advantageous effects of the microreactor were not observed with magnesium ortho-vanadate doped with palladium. With regard to the selectivity to propylene, the redox nature of the catalysts seemed to influence the performance of the microreactor.