Substrate processing method, substrate processing apparatus, and recording medium

The invention provides a substrate processing method, a substrate processing apparatus, and a recording medium. The substrate processing method includes: a fluid introduction step of introducing a processing fluid in a supercritical state into a processing container; a fluid holding step in which the inside of the processing container is maintained at a pressure at which the processing fluid can be maintained in a supercritical state; and a fluid supply/discharge step in which a pressure reduction step in which the pressure in the processing container is reduced until the discharge in the processing container which does not cause gasification of the processing fluid in the supercritical state reaches a pressure, and a pressure increase step in which the pressure in the processing container is increased until the discharge reaches a pressure which does not cause gasification of the processing fluid in the supercritical state. In the pressure reduction step, the fluid in the processing container is discharged b