A modular unit designed for the formation and study of cluster beams of inert and molecular gases is discussed. The results of the first experiments in studying the emission properties of cluster beams in the extreme ultraviolet range when excited by laser radiation or electron beams are presented. Cluster beams of inert and molecular gases of various sizes, structures, and compositions are used as targets. The carbon-dioxide emission spectra obtained by laser excitation are given and the observed lines are identified.