Cold atmospheric plasma (CAP) is a novel tool for various applications ranging from hygiene and cosmetics to medicine. In recent years, various CAP devices have been developed for medical applications especially for skin disinfection, blood coagulation, wound healing, and even for cancer treatment. CAPs have bactericidal, fungicidal, virucidal, and sporicidal effects due to the production of reactive species, ultra-violet radiation, electrons, ions, and so on. Therefore, CAPs have the potential for usage in hospital and personal hygiene. CAPs for medical purposes have to be designed individually, e. g. the dose and the plasma properties to eradicate bacteria from cell surfaces are different from the properties used to stop the proliferation of cancer. The CAP devices for medical purposes have to be designed in such a way, so that these are fully compatible with the international safety regulations (especially for the amount of produced reactive species, UV emission, and electrical current). However, the highest efficacy is reached by considering the combination of different CAP components (charged particles, reactive oxygen, and nitrogen species, heat, electric field, and photons), the way of application (direct or indirect with [ different distances from the target cell]), the different reaction phenomena in and around the target cell (cell membrane and intracellular biochemistry) along with the defense mechanisms in and around the target cells. Our group has developed a number of different CAP devices using the microwave technology (e.g. MicroPlaSter beta and NanoPlaSter), and the surface micro discharge technology (e.g. HandPlaSter, FlatPlaSter, CylindricalPlaSter, PersonalPlaSter, MiniFlatPlaSter). The strength, weakness, opportunity, and threat analysis show that the technique to use CAP for medical purposes is affordable, simple, easy to handle, and case sensitive - although more studies on the mechanism of the interaction of CAP and cells are necessary. However, the usage of CAPs in medicine - 'plasma medicine' - shows a newfangled hope for the development of molecular medicine in the near future possessing an immense market potentiality.