Abstract: In a supercritical fluid method a supercritical fluid is supplied into a process chamber. The supercritical fluid is discharged from the process chamber as a supercritical fluid process proceeds. A concentration of a target material included in the supercritical fluid discharged from the process chamber is detected during the supercritical fluid process. An end point of the supercritical fluid process may be determined based on a detected concentration of the target material.