The present invention relates to a substrate treatment apparatus and method which perform heat treatment on a substrate, and can accurately measure the temperature of the substrate even at a low temperature. An embodiment of the present invention includes a process chamber that has a substrate treatment space, a heating housing that contains a plurality of heating lamps for generating radiant energy, a window that is placed between the heating housing and the process chamber to maintain the air-tightness of the process chamber and transmit the radiant energy to be transferred to a substrate, a first pyrometer that measures a wavelength generated at the substrate in the process chamber, and converts the wavelength into substrate measurement energy, a second pyrometer that measures a wavelength generated at the window, and converts the wavelength into window measurement energy; and a heating controller that compensates for the window measurement energy in the substrate measurement energy, thereby calculating the temperature of the substrate itself, and uses the calculated temperature of the substrate itself to control the heating lamps.