PURPOSE: A door is provided to prevent accident caused by a gap between a door panel and a door frame and to reduce noise in opening and closing. CONSTITUTION: A door(10) comprises an auxiliary frame(20) and a barrier unit(40). The auxiliary frame is placed in a groove(11) formed on the four edges of the door and fixed with screws. The barrier unit is attached to the outer side of the auxiliary frame and protrudes from the side of the door. The bottom plate of the barrier unit is caught by a bent piece(12) of the door.
