OPENING DEVICE

To provide an opening device placed in an opening of a building capable of improving workability.SOLUTION: The opening device includes a frame member and an auxiliary frame member attachable to the frame member. The frame member has a protruding piece that protrudes toward the inner circumferential surface, and an engaging part is provided at the inner peripheral end of the protruding piece. The auxiliary frame member has two protruding pieces on the outer circumference, and in either one of the two pieces, an engaged part that engages with the frame member in the depth direction is provided therebetween. A protruding piece of the frame member is placed between the two pieces of the auxiliary frame member. When the engaging part of the frame member is engaged with the engaged part of the auxiliary frame member, and a fitting member is inserted from the inner circumferential side between one piece of the auxiliary frame member and the protruding piece of the frame member. With this, the movement of the auxiliary frame member relative to the protruding piece of the frame member is restricted and fixed.SELECTED DRAWING: Figure 11 【課題】建物の開口部に配置される開口部装置に対して、施工性を向上する。【解決手段】枠材と、枠材に取り付け可能な補助枠材を備え、枠材は、内周面に突出する突出片を有し、突出片の内周端に係合部が設けられており、補助枠材は、外周側に突出する二つの片を有するとともに、二つの片の間でいずれか一方の片に枠材の係合部が見込み方向に係合する被係合部が設けられており、補助枠材の二つの片の間に枠材の突出片が配置されて枠材の係合部が補助枠材の被係合部に係合されるとともに、補助枠材の一方の片と枠材の突出片との間に内周側から嵌入部材が嵌入されることで、枠材の突片に対する補助枠材の移動が規制されて固定されている。【選択図】 図１１