A method for drying a wafer at room temperature includes a cleaning step, a reacting step and a pressure releasing step. The cleaning step includes putting a processing workpiece into a cleaning solvent. The reacting step includes putting the processing workpiece along with the cleaning solvent into a reaction chamber, implanting a supercritical fluid into the reaction chamber, and increasing a pressure of the reaction chamber to dissolve the cleaning solvent in the supercritical fluid. A critical temperature of the supercritical fluid is below room temperature. The pressure releasing step includes releasing the pressure of the reaction chamber and discharging the supercritical fluid together with the cleaning solvent out of the reaction chamber, after completely dissolving the cleaning solvent in the supercritical fluid.