PURPOSE: A substrate processing apparatus is provided to increase substrate processing efficiency by collecting light from a thermal source unit through a reflector on the lower side of the thermal source unit. CONSTITUTION: An inner space is formed in a chamber(100). A heating unit set is separately arranged in the chamber in a vertical direction. A thermal source unit(200) emits light. A reflector reflects the light emitted from the thermal source unit. A support is installed on the upper side of the reflector.
