This paper provides a simple manner to demonstrate the vortex effect, occurring inside a plasma reactor operating at atmospheric pressure, used for CH 4 and CO 2 reforming and their conversion to high added value products. The reactor has a specific design to preheat the incoming gas and, at the same time, to cool the reactor bulk. The trace printed on the conical electrode and in the reactor bottom represents a clearly manifestation of the vortex effect. The reactor is also provided with a postchamber to prevent environment reaction and get an expansion in plasma volume sustaining a stable discharge operation.