The present invention relates to a substrate drying chamber. The present invention comprises: an upper housing; a lower housing; a sealing part; a substrate positioning plate; an upper supply port providing a supply path for a supercritical fluid for drying; an integrated supply/discharge port providing a supply path for a supercritical fluid for initial pressure and a discharge path for a mixed fluid in which an organic solvent has been dissolved into the supercritical fluid for drying after drying in accordance with the supply of the supercritical fluid for drying; and a check valve connected to the end of the upper supply port and preventing the mixed fluid from flowing backward to the upper supply port. The present invention can prevent the mixed fluid from being phase-separated and giving rise to particulate contamination on the substrate when the mixed fluid is discharged (decompressed) after the completion of a flushing process in which supplying of the supercritical fluid for drying and discharging of the mixed fluid, in which the organic solvent has been dissolved into the supercritical fluid for drying, are repeated.