PURPOSE: To provide a window structure which can be used as an emergency extrance and can be applied event to a dwelling house by reducing the area of an opening functioning as the emergency extrance installed to the external wall of a building and is maintained easily as cleaning from an indoor section.

CONSTITUTION: An opening-closing windows 5 are mounted into the window rails 7(7a-7d) of a window 4 which can be used as an emergency entrance. Consequently, the window 4 is used as a emergency entrance at the time of a disaster such as a fire. Only the opening-closing windows 5 are employed as ventilating windows, etc., at the time of normalcy, while the window 4 is closed. Accordingly, the window 4 can be opened and closed easily even at the time of normalcy.