A method for treating a substrate is provided. The method includes the following steps: performing a process of treating the substrate by dispensing a supercritical fluid onto the substrate. A treating fluid flows through a treating fluid supplying regulator regulating an amount of the treating fluid before dispensed onto the substrate. The treating fluid is heated to a set temperature or more by a first heater before passing through the treating fluid supplying regulator, and the treating fluid is heated by a second heater when the treating fluid is passed through the treating fluid supplying regulator. The temperature of the treating fluid is lowered in rear region of the treating fluid supplying regulator. The set temperature is a temperature that allows the lowered temperature to be maintained at a critical temperature or more.