This work is to study the plasma application using a capacitive discharge ignition capable of using the plasma jet which belongs to the non-thermal plasma physic. A plasma-jet spark plug was designed to combine a discharge chamber including an insulator and expanding the plasma area. The nonresistance was applied to acting the interference suppression of a plasma-jet spark plug to ensure the high energy generated at a DC-DC converter. An ANSYS FLUENT program was used to conduct analyzing combustion progress. The combustion simulation model is composed of configurations of a spark plug, a lambda sensor, and an internal combustion chamber. Resultantly, the minimum value of the combustion pressure is verified at λ = 1.6, and the plasma jet has higher values in the order of 2, 3, and 4 bar than the conventional models due to having a fast reaction. Consequently, the plasma jet has advantageous in combustion diffusivity in comparison to the conventional spark plug since the negative electrode of the cathode is not designed in front of a jet plug.