A screen is made to be able to be changed in a state in which the screen is made to be detachable from a screen attaching frame portion, a first connector is arranged at one end extracted from the screen of screen tension members penetrating the screen at a plurality of portions in a length direction, the one end is connected to a vicinity of a free end of a slide guide frame portion, other end of a jump member extracted to a screen attaching side is arranged with a second connector, the first connector and the second connector are made to be attachable and detachable to and from each other, and the slide guide frame portion is extracted from inside of the screen attaching frame portion.