Aspergillus flavus toxin contamination of pistachio nuts is a serious problem in terms of health and food security. In this paper, in order to increase the nut shelf life by eliminating or reducing the amount of toxin-producing fungus Aspergillus flavus, pistachios were irradiated with cold plasma, using Atmospheric Pressure Capacitive Coupled Plasma (AP-CCP) generating device using Argon gas. The advantages of this device are both its mobility, adjoining a nuts carrying container for thorough irradiation of the nuts and that the device can be designed in the form of an array of torches for treatment of large quantities of nuts in open air as against in a vaccum chamber. In this way, the sample of nuts are firstly soaked with fungus and then irradiated in different conditions in terms of power, pressure and time. The analysis of experimental results indicates 4 log (66.6%) fungus reductions. This pathogen reduction was observed in 100 Watts, at atmospheric pressure and irradiation duration of 10 minutes.