Recently, the medical applications of cold plasma have received a wide range of attention due to its high efficiency in treating a wide range of diseases, and the absence of collateral damage from its use on living tissues and organs. The DBD) plasma system was designed and built to produce a cold plasma that can be used for different applications. The system will have two electrodes and the applied voltage will be (8 and 10) kVp−p and the frequency will be almost (21kHz), the results of this study should that cold atmospheric plasma jet was generated with flowrate of 4 (slm) of different gases (Ar, He and mixed gases) and conditions to diagnose different characteristics. Staphylococcus aureus samples were obtained and cultured on a Mueller hinton agar. Then they were treated with cold plasma. The treatment periods were (5, 10, 15, 20) minutes. The results showed that the growth of bacteria-type cells decreases with increasing treatment period and thus leads to the killing of bacterial cells. Cold plasma technology is a promising and safe technology that has succeeded in eliminating Staphylococcus aureus bacteria without causing any damage to the living tissues.