PROBLEM TO BE SOLVED: To provide an inner structure of a canister, the canister, and a canister connected body, which prevent reduction of absorption performance due to water vapor condensation caused by absorption reaction, with a simple structure, enable a removal effect of water vapor contained in a circulating gas to be expected simultaneously, and also enable plural canisters to be connected in a cylindrical axis direction.SOLUTION: An inner structure 40 of a canister 20 includes: a transparent inner cylinder 41 which is arranged on an inner side of a cylindrical and transparent outer cylinder 30 and forms a double pipe together with the outer cylinder 30； an inflow opening part 45 arranged on a lower end of the inner cylinder 41； a carbon dioxide absorbent 43 accommodated in an inner space 42 of the inner cylinder 41 and absorbing carbon dioxide contained in a circulating gas； an outflow opening part 46 arranged on an upper end of the inner cylinder 41 and causing the circulating gas having passed the carbon dioxide absorbent 43 to outflow to an upper side； and a communication part 47 arranged on the upper end of the inner cylinder 41 and communicating an annular gap part 48 between the outer cylinder 30 and inner cylinder 41 with the inner space 42.【課題】 簡素な構造で吸収反応により生じた水蒸気の結露による吸収性能の低下を防ぐと同時に、循環ガスに含まれる水蒸気の除去効果も期待でき、しかも、複数のキャニスタを筒軸方向に連結可能なキャニスタの内部構造、キャニスタ及びキャニスタ連結体を提供する。【解決手段】 キャニスタ２０の内部構造４０は、筒状でかつ透明な外筒３０の内側に設けられ、外筒３０と二重管を形成する透明な内筒４１と、内筒４１の下端部に設けられる流入用開口部４５と、内筒４１の内側空間４２に収容され、循環ガスに含まれる二酸化炭素を吸収する二酸化炭素吸収剤４３と、内筒４１の上端部に設けられ、二酸化炭素吸収剤４３を通過した循環ガスを上方に流出させる流出用開口部４６と、内筒４１の上端部に設けられ、外筒３０及び内筒４１の間の環状の隙間部４８と内側空間４２を連通させる連通部４７と、を備える。【選択図】 図２
