An isolator includes: a working chamber in which work is conducted an atomizer configured to atomize air or a decontamination material in the working chamber: a pump configured to supply the decontamination material to the atomizer a compressor configured to supply air to the atomizer a pressure sensor configured to measure an internal pressure of the working chamber and a control unit configured to perform a leak test, in which the compressor is driven to supply air from the atomizer into the working chamber thereby pressuring the working chamber, and airtightness of the working chamber is tested based on the internal pressure of the working chamber measured by the pressure sensor.
