Helium non-thermal atmospheric pressure plasma is now increasingly widely used in medicine for the disinfection of wounds, local treatment of cancer and skin diseases of bacterial nature. The inhibitory effect of non-thermal plasma on the growth of microorganisms with simultaneous stimulation of proliferation of wound skin cells was shown. The aim of this study was to determine the effect of helium plasma jet atmospheric pressure on the morphophysiological properties of bacteria and bacterial biofilms in infected skin wounds of animals. For the generation of non-thermal plasma, the author's development of a barrier discharge source was used. Experiments were carried out on white mongrel mice. Antimicrobial and wound healing activity of non-thermal plasma was determined at the electron microscopic level. As a result of the impact of non-thermal plasma on the skin wounds of animals shows the microbial death on the surface and in the thickness of the scab, as well as the absence of bacterial biofilms in the upper layers of the wound surface.