An isolator includes: a contamination-target chamber including an inlet and outlet having intake and discharge filters, respectively and a decontaminating-gas-supply unit to supply decontaminating gas into the chamber without flowing through the filters, the unit including: an atomizer including first and second ports and a nozzle a first pipe having one and the other ends connected to a compressor and the first port, respectively a second pipe having one end connected to the second port and the other end open a reservoir a pump to take in decontamination solution from the reservoir and a third pipe, having one end connected to the pump, thorough which the solution flows, the atomizer configured to, when injecting from the nozzle intake air from the first port, suction the solution, via the second pipe, by negative pressure produced in the second port and inject the solution in an atomized state, mixing it with air.
