PURPOSE: To provide an opening window installed even in a narrow place while enabling especially ventilation, lighting and approach at the emergency time.

CONSTITUTION: In the structure with a handrail 10 and a sliding screen enabling lighting and ventilation provided parallelly at an emergency exit opening part 11, pins 17 are inserted into pin holes 16 provided at both end parts of the upper lateral sash bar 12 of the handrail 10 and the brackets 15 thereof so as to lock the handrail 10 to the emergency exit opening part 11. At the emergency time, the handrail 10 can be removed from the emergency exit opening part 11 by pulling the pins 17 out of the pin holes 16.