Abstract: A device for shielding a leakage of high frequency waves in a microwave oven, capable of effectively shielding high frequency waves leaked without using any ferrite rubber and reducing the thickness of a door of the microwave oven to achieve a compactness of the microwave oven. The device includes an outer panel, an inner panel fixedly mounted to the outer panel to define a choke channel therebetween, the inner panel having a first bent portion and a second bent portion, a pair of capacitive seals provided at portions of the inner panel facing a front panel of the microwave oven, a plurality of slits formed at the first bent portion at intervals and adapted to attenuate high frequency waves advancing in a X-axis direction, and a choke cover fitted in the second bent portion and adapted to close an opened portion of the choke channel.