An object of the present invention can be retrofitted easily without processing the pet door to an existing door, to provide door pet doorway structure that can be returned to its original state when not in use. A auxiliary door the elongated body of the same height as the screen door 1 to form an opening of a size small animal pet can pass, pet linked freely bend the upper door 4a and lower door 4b into and out in both directions the door 4 is suspended freely swinging to and from both directions in the opening to the pet out for auxiliary door 3. When used, by opening the amide 1 halfway to place the pet out auxiliary door 3 between the screen door 1 and the door frame 2 is mounted so as to sandwich the pet out auxiliary door 3 closing the amide 1. When not in use is to be opened amide 1 may remove the pet out auxiliary door 3, it is also possible to remain attached. .BACKGROUND【課題】既設の戸にペット用扉を無加工で容易に後付けでき、不使用時には元の状態に戻すことができる戸のペット出入り口構造を提供する。【解決手段】網戸1と同じ高さの細長の補助戸本体に小動物のペットが通過できる大きさの開口部を形成し、上扉4aと下扉4bを出入り両方向へ屈曲自在に連結したペット用扉4を前記開口部に出入り両方向へ揺動自在に吊り下げてペット出入り用補助戸3とする。使用するときは、網戸1を途中まで開けてペット出入り用補助戸3を網戸1と戸枠2の間に配置し、網戸1を閉めてペット出入り用補助戸3を挟むようにして取り付ける。不使用時は、網戸1を開けてペット出入り用補助戸3を取り外しても良いし、取り付けたままの状態にしても良い。【選択図】図1
