The present invention does not have disinfection effects obtained by the air curtains, even insects that would jump over possible suction slit portion, providing insects intrusion preventing device capable of suppressing the intrusion of the entrance portion . In A insects intrusion preventing device 11, the wall portion 27 and the entrance portion 21 which is formed by the exception to the floor surface 31 of the floor 29, the floor surface to the floor portion 29 across the opening frontage opposite ends 35 of the inlet and outlet section 21 31 from the entrance part 21 is recessed to a recessed portion 13 in a direction away to the outside is formed with a predetermined distance, inwardly in the recesses opening region of the recess 13 and is formed with a water gradient in approximately the same range that the inclined surface, a supply water path for supplying water to the inclined surface is connected to the inclined upper edge of the inclined surface, a drainage channel for draining water that flows down the inclined surface is connected to the inclined lower edge of the inclined surface, the provided. .BACKGROUND【課題】エアカーテンによる駆除効果が得られず、吸引可能なスリット部を飛び越えてしまうような昆虫類であっても、出入口部からの侵入を抑止することができる昆虫類侵入防止装置を提供する。【解決手段】昆虫類侵入防止装置11において、壁部27を床部29の床面31まで除いて形成した出入口部21と、出入口部21の開口間口方向両端35に渡る床部29に床面31を凹ませて出入口部21から外側へ離反する方向に所定距離を有して形成される凹部13と、凹部13の内側で凹部開口領域とほぼ同等の範囲で水勾配を有して形成される傾斜面と、傾斜面の傾斜上縁に接続されて傾斜面に水を供給する供給水路と、傾斜面の傾斜下縁に接続されて傾斜面を流下した水を排水する排水路と、を設けた。【選択図】 図1
