###### Abstract  
Atmospheric pressure plasmas represent a feasible and eco-friendly alternative to conventional physicochemical methods used in technology today for facing materials. The complex physical and chemical processes occurring when plasma interacts with mater offer a rich source of short- and long-lived chemical species, mostly reactive nitrogen and oxygen species (RNS/ROS). They are also crucial for many applications ranging from the food industry, environmental related fields, agriculture and healthcare, to material science and even automotive. Exciting novel applications of plasma-surface, plasma-liquid, and plasma-gas interactions are at the focus of many challenging multidisciplinary scientific inquiries. The range of potential plasma applications is broad, from plasma (bio)medicine (antibacterial/disinfectant/antiseptic agent, wound healing promoter, selective treatment of cancer cells and tumors), plasma pharmacology, plasma and food, plasma bioengineering, plasma agriculture (as seed germination inducer or even as a green fertilizer), to plasma and automotive. Nevertheless, all of these plasma fields are plasma-based technologies. This Special Issue on 'Frontiers in Atmospheric Pressure Plasma Technology' was focused on, but not limited to, recent findings in novel and possible future applications of plasmas in life sciences, biomedicine, agriculture, and the automotive industry. Papers providing fundamental insights into the understanding of plasmas and detailed analysis of electrical discharges, pushing forward cutting-edge techniques in plasma science and technology, were especially welcomed and received. On the basis of the background outlined above, this Special Issue of _Applied Sciences_ entitled \"Frontiers in Atmospheric Pressure Plasma Technology\" includes eight original papers [1, 2, 3, 4, 5, 6, 7, 8] and two reviews [9, 10] providing new insights into the application of atmospheric pressure plasma technology. [PERSON] et al. [1] used atmospheric pressure plasma irradiation to facilitate transdermal permeability of aniline blue on porcine skin and increase the cellular permeability of keratinocytes and further demonstrated the production of nitric oxide from keratinocytes. Their findings suggest a promoting effect of low-temperature plasma on transdermal absorption, even for high-molecular-weight molecules, as well as that the plasma-induced nitric oxide from keratinocytes is likely to regulate transdermal permeability in the epidermal layer. [PERSON] et al. [2] showed in their study the inhibitory effect of cold atmospheric plasma (CAP), running in helium, on chronic wound-related multispecies biofilms. The report describes the effect of He-CAP on wound-related multispecies biofilms and confirms the safety of the protocol. It was proven that exposure to He-CAP for 5 min provides inhibitory effects for the wound-related multispecies biofilms formed by methicillin-resistant _Staphylococcus aureus_ (MRSA), _Pseudomonas aeruginosa_ and also _Enterococcus faecalis_. Furthermore, [PERSON] et al. [3] revealed the effects of O\({}_{2}\) addition on the discharge parameters and production of reactive species of a transferred atmospheric pressure plasma jet produced at the tip of a long and flexible plastic tube. They concluded that the addition of O\({}_{2}\) to the working gas seems to be useful for increasing the effectiveness of the plasma treatment only when the target modification effect is directly dependent on the content of atomic oxygen. In a report by [PERSON] et al. [4] the role of HNO\({}_{2}\) in the generation of plasma-activated water by air transient spark (TS) discharge, a DC-driven self-pulsing discharge generating a highly reactive atmospheric pressure air plasma, was studied.