Experimental aspects of spectroscopic studies of large tokamak plasma are reviewed. Problems in the measurements of impurity contents and some possibility of ion temperature measurement using forbidden lines from highly ionized ions are discussed. Significance of charge exchange recombination process during neutral particle injection is also discussed. Relating to the impurity control, requirement for polychromator in the XUV region is em-phasized and some examples of gratings and multi-channel detector which are suitable for the XUV polychromator are given.
