PROBLEM TO BE SOLVED: To provide an arm device which facilitates securing of an operational range of an instrument in endoscopic surgery or the like.SOLUTION: A first gimbal part 21 which supports an instrument 90 to rotate about a first rotational axis 101 extending along an axis line of the instrument 90, a second gimbal part 22 which rotates the instrument 90 about a second rotational axis 102 extending in a direction intersecting relative to the first rotational axis 101, and a tip end part 30 which rotates the instrument 90 about a third rotational axis 103 extending to intersect a plane including the first rotational axis 101 and the second rotational axis 102 are provided. The third rotational axis 103 has an inclination angle that is greater than 0 degree and smaller than 90 degrees when a horizontal direction is 0 degree, and an upward position in a vertical direction is 90 degrees.SELECTED DRAWING: Figure 3【課題】内視鏡外科手術等における器具の操作範囲の確保が容易なアーム装置を提供する。【解決手段】器具９０の軸線に沿って延びる第１回転軸１０１まわりに器具９０を回転可能に支持する第１ジンバル部２１と、第１回転軸１０１に対して交差する方向に延びる第２回転軸１０２まわりに器具９０を回動させる第２ジンバル部２２と、第１回転軸１０１および第２回転軸１０２を含む平面に対して交差して延びる第３回転軸１０３まわりに器具９０を回動させる先端部３０と、が設けられ、第３回転軸１０３は、水平方向を０度とし垂直方向の上方を９０度とした際に、０度よりも大きく９０度よりも小さな傾き角度を有することを特徴とする。【選択図】図３
