Design, construction, and experimental investigation of the plasma water activation device have been presented in this article. In this design, one of the electrodes, which is plate ss316, is placed in water. The other electrode which is made from tungsten is placed inside a glass tube and immersed in water. Air is also blown into the water through a constant rate air pump of 5 L.min-1. An AC power supply with voltage and current of 15 kV and 30 mA has been used to create plasma in water. The results of the analysis of nitrite, nitrate, and pH in three water samples that have been irradiated with plasma for 10, 20, and 30 minutes showed a very significant change compared to the control sample. The pH of PAW is drastically decreased with an increase in treatment time due to the formation of strong acids. Nitrite and nitrate concentrations of PAW are increased with an increase in treatment time.