A continuous production of hydrogen and carbon black from methane without CO2 emission in atmospheric pressure has been investigated by non thermal decomposition of methane using a system of direct current (DC)-spark discharge plasma, which has great advantages over other systems, like thermal plasma or catalytic conversion of methane in H-2 production. A plasma reactor with specific design of electrodes was employed to examine the reactor performance regarding operating conditions such as feed flow rate, input power and electrodes distance. The experimental results showed that designed reactor increases not only the concentration of the produced hydrogen in continues condition but also guarantees stable plasma. As the methane supply rate increased, the hydrogen concentration decreased but on the other hand the hydrogen volume flow rate increased. In general, under the specified operating condition (power = 21 W and methane flow rate = 150 ml/min), the plasma converter produced a hydrogen concentration of 45 % at hydrogen volume flow rate of 75 ml/min.