To effectively eliminate radiation outside the band with a wavelength of 13.5 nm which has adverse effects on exposure without reducing the intensity of the EUV radiation with a wavelength of 13.5 nm, in an extreme UV radiation exposure tool which has an extreme UV radiation source device with an EUV focusing mirror which focuses extreme UV radiation and radiation outside the band which is emitted by the high density and high temperature region of a plasma, an illumination optical system for projecting this radiation onto a mask, and a projection optical system which projects the radiation from the mask onto a workpiece, a radiation shield is provided of a size which enables the radiation emerging from the EUV focusing mirror to be completely incident on it, and which has an opening of a size which results in essentially only extreme UV radiation being transmitted through it.