An isolator includes: a chamber to be decontaminated including an inlet provided with an intake filter and an outlet provided with a discharge filter a first flow path through which outside air is taken into the chamber via the intake filter a second flow path through which gas in the chamber is discharged via the discharge filter a blower configured to take in the outside air to the chamber through the first flow path, as well as produce an air current to discharge the gas in the chamber through the second flow path a decontaminating gas supply unit configured to supply decontaminating gas into the chamber without flowing through the intake filter and the discharge filter and a third flow path through which the gas in the chamber is discharged via the intake filter when the decontaminating gas is supplied into the chamber.
