A semiconductor manufacturing facility includes: a process chamber in which an amorphous carbon layer (ACL) process in which amorphous carbon is deposited so that an ACL is formed, is performed; a vacuum pump in which a residual gas generated in the process chamber is discharged from the process chamber while the ACL process is performed; a chamber exhaust pipe through which the process chamber and the vacuum pump communicate with each other; a plasma reactor configured to form a plasma reaction region using plasma; and a gas supplying device configured to supply a treatment gas to the plasma reactor.