In an extreme ultra violet light source apparatus of a laser produced plasma type, charged particles such as ions emitted from plasma are promptly ejected to the outside of a chamber. A first image pickup device includes a first photographing optical system that can change the focal distance and a CCD for converting a subject image formed by the first photographing optical system into an image signal. The result is that the overall jewelry chain appears as an integral and homogenous chain having a consistent aesthetic appearance.