An extreme UV radiation producing device in which adhesion of solid tin in the vacuum pump of an evacuation device is restricted, so that the maintenance period and the replacement period of the pump is prolonged is achieved by the provision of a treatment unit between a radiation source chamber and the evacuation device. The treatment device has a hydrogen radical producing part in which tin and/or a tin compound in the evacuated gas from the radiation source chamber is/are made into a tin hydride; and a heat treatment part in which the tin hydride is thermally decomposed and in which the tin produced liquefied and separated from the evacuated gas. The liquid tin is fed into a collecting/storage vessel and the evacuated gas from which the tin and/or a tin compound has been removed fed to the evacuation device.