Microwave plasmas have been used as sources for atomic spectroscopy since the 1970s. Several common forms of this plasma source exist, including the microwaveinduced plasma, the capacitively coupled microwave plasma, the surface-wave or surfatron plasma, the microwave plasma torch, and some other unique designs. Although not as popular as the inductively coupled plasma, microwave plasmas offer the advantage of lower initial and operational costs. This review covers the literature on the various forms of the microwave plasma since 1985, including basic principles of microwave plasmas and design descriptions of a variety of systems.