PROBLEM TO BE SOLVED: To provide a ventilation system for a strong vinyl greenhouse in which a window for ventilation can be easily attached to any site, the ventilation system being low cost, and hardly influenced by wind, in a vinyl greenhouses using steel pipes as a framework.SOLUTION: A vinyl greenhouse using steel pipes 2 as a framework comprises: a window frame member 3 equipped with a center opening capable of attachment to any site on at least two or more steel pipes 2 which are adjacent and parallel to each other in the vinyl greenhouse； an attaching member 6 for fixing the window frame member 3 to the steel pipes 2； a fixing tool for sandwiching and fixing the vinyl at the external side face and upper face of the window frame member 3； a window member 4 which covers the window frame member 3； and a connection member 5 which connects the window member 4 and the window frame member 3. A groove for fixing the vinyl on the external side face and upper face of the window frame member 3 is also provided to sandwich and fix the vinyl by the fixing tools.SELECTED DRAWING: Figure 2【課題】鋼管を躯体とするビニールハウスにおいて、任意の場所に、換気の為の窓を簡単に取り付けることが可能で、低コストで、風の影響を受けにくい堅牢なビニールハウス用換気装置を提供する。【解決手段】鋼管２を躯体としたビニールハウスにおいて、ビニールハウスの隣り合う平行な少なくとも２本以上の鋼管２上の任意の場所に取り付け可能な中央開口部を備えた窓枠部３と、窓枠部３を鋼管２に固定するための取付部６と、ビニールを窓枠部３の外部側面と上面に狭持固定する固定具と、窓枠部３を覆う窓部４と、窓部４と窓枠部３を接続する接続部５を備えた構成とした。また、窓枠部３の外部側面と上面に、ビニールの固定のための溝を設け、固定具により、ビニールを挟持固定する構造とした。【選択図】図２
