PURPOSE: A shielding unit of a door for a shelter box is provided to maintain door locked without locking a door lock by pressing a first shielding unit. CONSTITUTION: A first shielding unit(11) is formed along the inner edge of a door(2) for a sector box. A pair of second shielding units(12) is formed along the rim of a doorframe corresponding to the first shielding unit. A guide unit(13) is formed between second shielding units to provide a space for staying electromagnetic wave. A shielding unit(14) is combined in the second shielding unit in order to press the first shielding unit. The shielding unit absorbs and reflects electromagnetic wave.
