PROBLEM TO BE SOLVED: To easily and quickly attach/detach a surgical instrument part to/from a surgical instrument driving part in an operation support device.SOLUTION: The operation support device 50 includes a connection body in which an intermediate member support body 2a for retractably supporting an intermediate shaft 2b inside and a surgical instrument support body 1a for retractably supporting an input side transmission shaft 1A inside are detachably connected to each other along the direction of movement of the intermediate shaft 2b and the input side transmission shaft 1A. The operation support device 50 further includes: a first shaft engaging part provided in one of the intermediate shaft 2b or the input side transmission shaft 1A； a shaft connection member provided in the other of the shafts and having a connection engaging part to be engaged with the first shaft engaging part； and a shaft fixing member configured to be movable with respect to the intermediate shaft 2b or the input side transmission shaft 1A and configured to selectively form a shaft engagement fixing state in which the engagement state is fixed by pressing the connection engaging part so that the connection engaging part is engaged with the first shaft engaging part, or a shaft engagement releasing state in which the pressure of the connection engaging part is released, according to the position of movement.【課題】手術支援装置において術具部の術具駆動部に対する着脱を容易かつ迅速に行うことができるようにする。【解決手段】内部に中間軸２ｂを進退可能に支持する中間部材支持体２ａと、内部に入力側伝達軸部１Ａを進退可能に支持する術具部支持体１ａとが、中間軸２ｂおよび入力側伝達軸部１Ａの移動方向に沿って着脱可能に連結された連結体を含む手術支援装置５０であって、中間軸２ｂおよび入力側伝達軸部１Ａの一方に第１の軸係合部、他方に設けられ、第１の軸係合部に係合する連結係合部を有する軸連結部材と、中間軸２ｂまたは入力側伝達軸部１Ａに対して移動可能に設けられ、移動位置に応じて、連結係合部が第１の軸係合部に係合するように連結係合部を押さえて係合状態を固定した軸係合固定状態と、連結係合部の押えを解除した軸係合解除状態とを選択的に形成する軸固定部材と、を備える。【選択図】図２
