The EM analysis of RF leakage radiation from microwave oven has been carried out using FDTD method in this paper. Here the microwave oven structure is modeled as rectangular cavity. The leakage through the gap between the door and the oven cavity, which is the most probable path of leakage of radiation, is determined using FDTD method. Further, the far-field radiation pattern of microwave oven is computed by the far-field transformation of Huygen's equivalent sources using Green's function. It is found that the RF leakage from microwave oven has a characteristic interference far-field pattern.