A provided emergency stop facility includes an alternative gas supply facility capable of supplying a cooling medium in a refining device as an alternative gas instead of an entrained gas shut-off by closure of an entrained gas shut-off valve with loss of a driving source caused by the emergency stop; an alternative entrained gas shut-off valve switching between supply and shut-off of an alternative gas to a hydrogen fluoride supply passage; and an instrumentation gas supply facility for emergency stop having an instrumentation gas shut-off valve enabling supply of an instrumentation gas by opening with loss of the driving source caused by the emergency stop, wherein at the emergency stop of the fluorine gas generating apparatus, the alternative entrained gas shut-off valve is opened upon receipt of the supply of the instrumentation gas, and the alternative gas is supplied to the hydrogen fluoride supply passage.