The principal applications of Radio Frequency (RF) capacitive discharges are excitation of an active medium in gas lasers, primarily in CO2 lasers, and materials treatment by bombarding targets with ions accelerated in space charge sheaths. This chapter is concerned with RF discharge application to laser construction and considers materials treatment to help the layman to get a general idea of technological processes implemented by means of RF discharges. It emphasizes that the possibility of regulating plasma parameters by choosing the frequency is an essential advantage of RF laser excitation. The chapter focuses on diffusion-cooled lasers, which clearly show the advantage of RF excitation. It considers the problem of plasma parameter regulation by choosing suitable frequencies is of great importance for laser construction. The chapter discusses processes that involve the use of plasmachemical reactors with an RF capacitive discharge. The basic processes in ion-plasma treatments are ion-plasma etching and deposition of thin films and coatings.