PROBLEM TO BE SOLVED: To provide a ventilation device capable of opening and closing a ventilation window by one operation means.SOLUTION: There is provided a ventilation device which comprises: a window frame 1 provided in a structure； a ventilation window 2 which has a supported part supported by the window frame 1 at the upper end part and is provided to be freely opened/closed around the supported part with respect to the window frame 1； a support arm 3 which extends at a position below the supported part of the ventilation window 2 to a position where the support arm is protruded from the window frame 1 toward an opposite side to the side where the ventilation window 2 is provided； an operation rod 4 which is pivotally supported at a position of protruding from the window frame 1 of the support arm 3 and can be moved vertically； and a guide member 5 which guides the movement of the operation rod 4 at a position opposite to the side where the ventilation window 2 of the window frame 1 is provided and can be engaged at a predetermined position of the operation rod 4 to fix the opening/closing angle of the ventilation window 2.【課題】１つの操作手段によって換気窓を開閉することが可能な換気装置の提供。【解決手段】構造物に設けられる窓枠１と、上端部に窓枠１に支持される被支持部を有し、窓枠１に対向して被支持部を中心として開閉自在に設けられる換気窓２と、換気窓２の被支持部より下の位置に、換気窓２が設けられた側とは逆側に向かって窓枠１から突出する位置まで延設された支持アーム３と、支持アーム３の窓枠１から突出する位置に軸支され、上下方向に移動可能な操作杆４と、窓枠１の換気窓２が設けられた側とは逆側で操作杆４の移動をガイドするガイド部材５であり、操作杆４の所定の位置に係合して換気窓２の開閉角度を固定可能なガイド部材５とを有する。【選択図】図２
