Apparatus for processing a substrate and method of operating the same

An apparatus for processing a substrate, the apparatus including an internal space divided into a plurality of sub-spaces in a vertical direction, the apparatus comprising:

• a reaction tube arranged at the internal space, the reaction tube that processes a plurality of substrates stacked in the vertical direction;
• a side cover arranged to surround the reaction tube, the side cover including a plurality of gas transmission holes arranged along the vertical direction at a selected portion of the side cover;
• and
• a heater arranged between the reaction tube and the side cover, the heater including a plurality of unit heaters for each of the plurality of sub-spaces, the plurality of unit heaters separated by a is plurality of first holes,
• wherein each of the unit heaters includes an adiabatic block for surrounding the reaction tube, the adiabatic block including a plurality of second holes radially formed therein and divided into a plurality of adiabatic regions;
• and a coil arranged on an inner surface of the adiabatic block,
• wherein a cooling gas is transmitted through the plurality of first holes and the plurality of second holes, and temperature of the adiabatic block is lowered by the cooling gas flowing through the plurality of first and second holes.