Master arm and robot. The master arm includes: a support member (1)； a shoulder member (2) rotatably connected to the support member (1)； an elbow member (4)； the shoulder member (2) and the elbow member (4). ) Is rotatably connected to the upper arm member (3)； and the forearm member (5) is rotatably connected to the elbow member (4). An upper arm part (30) and a second upper arm part (31) are provided, and the first upper arm part (30), the second upper arm part (31), the shoulder member (2), and the elbow member (4) are connected. A parallelogram can be formed by an imaginary line that sequentially connects the points with a straight line, the first rotary joint is disposed between the support member (1) and the shoulder member (2), and the second rotary joint is First upper arm (30) and the shoulder Is disposed between the member (2) and the third revolute joint is disposed between the elbow member (4) and the forearm member (5), and the axis of the first revolute joint is of the third revolute joint. It is parallel to the axis and the axis of the second rotary joint is perpendicular to the plane defined by the axis of the first rotary joint and the axis of the third rotary joint. The space occupied by the master arm based on the parallelogram and the joint arrangement is smaller, has a more stable structure and high rigidity, and can achieve a perfect balance of self-gravity. As a result, accuracy, flexibility, and comfort of operating the master arm can be improved. [Selection diagram] Figure 1マスタアームとロボット。前記マスタアームは：サポート部材（１）；前記サポート部材（１）に対して回転可能に接続されたショルダ部材（２）；エルボ部材（４）；前記ショルダ部材（２）と前記エルボ部材（４）に対して回転可能に接続された上腕部材（３）；および前記エルボ部材（４）に対して回転可能に接続された前腕部材（５）を備え、前記上腕部材（３）は、第１上腕部（３０）と第２上腕部（３１）を備え、前記第１上腕部（３０）、前記第２上腕部（３１）、前記ショルダ部材（２）、および前記エルボ部材（４）の接続点を直線で順次接続する仮想線によって平行四辺形が形成可能であり、第１回転ジョイントが前記サポート部材（１）と前記ショルダ部材（２）との間に配置され、第２回転ジョイントが前記第１上腕部（３０）と前記ショルダ部材（２）との間に配置され、第３回転ジョイントが前記エルボ部材（４）と前記前腕部材（５）との間に配置され、前記第１回転ジョイントの軸は前記第３回転ジョイントの軸と平行であり、前記第２回転ジョイントの軸は前記第１回転ジョイントの軸と前記第３回転ジョイントの軸が
