The existence of premixed ammonia/hydrogen/air steady flame have been numerically investigated in a micro-scale combustor. The impact of inlet flow velocity and hydrogen mole fraction of the fuel on the combustion characteristics are discussed. It has been found that when the inlet veloc-ity is too low compared to the flame speed or too high relative to the heating condition, either the steady flame cannot sustain itself or the auto ignition does not take place. The effect of these different parameters are reported as a map to show the region in which steady flame exists. It has been also observed that the flame location changes, going further into the channel toward the downstream by increasing inlet flow velocity or de-creasing hydrogen mole fraction. In term of emission, NO emission increases by decreasing the hydrogen mole fraction of the fuel as a re-sults of the combustion of ammonia.

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