PROBLEM TO BE SOLVED: To provide a sheath device for an endoscope system capable of reducing in-channel contamination of the endoscope system.SOLUTION: A sheath device for an endoscope system has: a contamination preventing sheath 23 which is formed into a cylindrical shape for inserting a treatment instrument 32 and has a sheath curved part at the end and a curve operation part 21 which is connected to a rear end of the contamination preventing sheath 23 and performs curve operation of the sheath curved part. A balloon 30 which inflates/deflates by the air being supplied or sucked via an air duct at a position in contact with an inner wall of a treatment instrument insertion channel 121 excluding the endoscope curved part when the treatment instrument 32 is protruded from the treatment instrument insertion channel 121 of the endoscope system insertion part 120 is arranged on an outer circumference of the contamination preventing sheath.SELECTED DRAWING: Figure 2ACOPYRIGHT: (C)2018,JPO&INPIT【課題】内視鏡システムのチャネル内汚染を低減することができる内視鏡システム用のシース装置を提供すること。【解決手段】処置具32を挿通するために円筒形状に形成され、先端にシース湾曲部を有する汚染防止シース23と、該汚染防止シース23の後端に接続されて該シース湾曲部を湾曲操作するための湾曲操作部21とを備え、内視鏡システム挿入部120の処置具挿通チャネル121から処置具32を突出したときに内視鏡湾曲部を除いた処置具挿通チャネル121の内壁と接する位置に空気路を介して空気が供給又は吸引されることにより膨縮するバルーン30を汚染防止シース外周に配置した内視鏡システム用のシース装置。【選択図】図2A
