To easily fit a wing to a fixed frame, by providing fixed side hinges at both side faces of the fixed frame body and providing rotary side hinges at both sides of the wing like a window and connecting both hinges by shaft pins.

The first regulating projection 6 and the second regulating projection 7 are provided at both side faces of a fixed frame body 1. And the main bodies 3 of the fixed side hinges 8 provided with a bearing wall 4 are fixed thereto and the main bodies 10 of the rotary side hinges 14 provided with a bearing wall 11 are fixed to both side faces of the wing 9. When fitting the wing 9 to the fixed frame body 1, the wing 9 is horizontally set and the bearing walls 4 of the fixed side hinges 8 and the bearing walls 11 of the rotary side hinges 14 are positioned to butt each other and shaft pins 15 are inserted in the shaft holes 12 of the rotary side hinges 14 and the shaft holes 5 of the fixed side hinges 8 to screw the male screw 15a into the female screw 12a of the shaft holes 12 and fix therein. Accordingly, the wing 9 can be fitted in an easier posture by minimum operators.