Stable combustion in a harsh environment, such as lean fuel concentration and/or low temperature conditions, is attractive because of its low emissions. However, such flames suffer from lack of stability. In our research, an AC plasma discharge is applied to a lifted jet flame to increase the stability of the flame. Two types of discharges are utilized for this experiment. First, a single electrode diffuse discharge (SEDD) directly to the liftoff flame base is investigated. Second, a dielectric barrier discharge (DBD) is achieved by adding a quartz coated secondary electrode. To quantify the stability, we measure the jet velocity and coflow velocity corresponding to liftoff and/or blowout points for both cases. We find that addition of a very small amount of energy (less than 0.01% of the energy of main system) to the flow in the form of these types of discharges significantly improves the flame stability. For example, we observe that the SEDD increases the liftoff stability limit by 30% in terms of coflow speed. In addition, it shows a self-adjusting feature of the discharge angle such that the stabilization can be achieved regardless of orientation and location of the electrode over a relatively broad range of conditions. In case of DBD, we find a more intense stabilization effect, 50% of the improvement in terms of coflow speed, than the single electrode discharge as well as a self-ignition ability, which is not found in the first type of discharge. In addition, we believe that the essential characteristic of the non-equilibrium state of the DBD due to its short pulse duration enables the targeting of energy deposition in an efficient way.