PROBLEM TO BE SOLVED: To provide a cannula device facilitating and ensuring attachment/detachment of a connector between tubes of a nasal cannula and a supplying tube in a respiration-gas supplying device side.SOLUTION: The cannula device includes: a nasal cannula having nasal tubes; respiration-gas flow tubes connected to the nasal cannula; an adaptor pipe connected to the respiration-gas flow tubes; a connector pipe removably attached to the adaptor pipe; and a respiration-gas supplying tube connected to the connector pipe. One of the adaptor pipe and the connector pipe is a female member having a receiving part and the other is a male member having an inserting part; and the male member is removably inserted into the female part. The cannula device further includes: a ring-shape part formed on a base-end part of the inserting part as a protruding ridge or a recessed groove extending on whole circumference thereof; and a lock piece formed on the receiving part, having a projection part locking the ring-shape part of the inserting part inserted in the receiving part.SELECTED DRAWING: Figure 4【課題】鼻孔カニューラのチューブと呼吸気体供給装置側の供給チューブとの間のコネクタの着脱を容易かつ確実にしたカニューラ装置を提供することを目的とする。【解決手段】鼻孔管を有する鼻孔カニューラと、前記鼻孔カニューラに接続する呼吸用気体流通用チューブと、前記呼吸用気体流通用チューブに接続されたアダプタ管と、前記アダプタ管に着脱自在に接続されるコネクタ管と、前記コネクタ管に接続された呼吸用気体供給用チューブとを備え、前記アダプタ管および前記コネクタ管は、いずれか一方が受入部を有する雌部材、他方が挿入部を有する雄部材として互いに挿脱自在に設けられ、このカニューラ装置はさらに前記挿入部の基端部の外面に設けられ周方向全周に延びる突条または凹溝からなるリング状部と、前記受入部に設けられ該受入部に挿入された前記挿入部の前記リング状部を係止する突起部を有するロック片とを有する。【選択図】 図4