This paper presents results of experimental studies carried out with atmospheric pressure non -thermal plasma jet, ANPJ, device energized by a low-cost Neon power supply of (10 kV, 30 mA, and 20 kHz). The discharge takes place by using compressed Air and N 2 gas separately with a flow rate from 3 to 25 L/min and charging voltage of 6 kV. All the results are taken during a period time of 100 μs. The excitation electron temperature has been measured using the photomultiplier tube, PMT, with two different wavelength filter s of 460 and 500 nm. The plasma jet device operational time effect on the temperature of the device components has been studied by using a thermometer. Scanning electron microscope, SEM, images were taken to visualize the changes in the surface of Polyethy lene terephthalate, PET before and after treatment with N 2 and Air Plasma Jet separately, and at optimum operation condition of plasma jet device.