Provided is a substrate treating method. The substrate treating method includes: a first supercritical processing operation of loading a first substrate into a supercritical chamber and supercritically processing the first substrate in the supercritical chamber; a resting operation of maintaining the supercritical chamber in an empty state for a first time until a temperature in the supercritical chamber becomes a preset temperature by opening the supercritical chamber after the first substrate is unloaded from the supercritical chamber; and a second supercritical processing operation of loading a second substrate into the supercritical chamber and supercritically processing the second substrate in the supercritical chamber.