To enable a person to get out of the inside by opening a fastener even when the fastener is closed while he/she stays inside a booth for sterilizing treatment for ozone sterilization.

This booth forms a sterilizing treatment space by being surrounded with a gas non-permeable sheet 21. An airtight fastener 23 having a manipulator 23a to be opened/closed from the outside is attached to an outlet/ inlet port 24 provided at one part of the sheet 21. Near the air-tight fastener 23, air tight bags 27A and 27B are projected while being sized enough for inserting hands from the inside of the sterilizing treatment space and the hands are put into the bags so as to hold the manipulators of the air-tight fastener.