Provided is a substrate processing apparatus. The substrate processing apparatus includes a tube having an inner space, a substrate support on which a plurality of substrates are stacked in multistage within the tube, the substrate support individually defining a plurality of processing spaces in which the plurality of substrates are respectively processed, a first gas supply part configured to supply a first gas into all the plurality of processing spaces, a second gas supply part comprising a plurality of injectors disposed to respectively correspond to the plurality of processing spaces so that the second gas is individually supplied onto each of the plurality of substrates, and an exhaust part configured to exhaust the gases within the tube. Thus, the gas may be individually supplied into each of the processing spaces in which the plurality of substrates are respectively processed.