PROBLEM TO BE SOLVED: To provide a medical support arm device with improved safety, that is stopped when a power supply is cut off, and enables continuation of a surgery even in a power loss, and medical observation device.SOLUTION: The medical support arm device includes brake mechanisms 370 at a plurality of joint parts constituting an arm part, for releasing a rotary shaft of the joint part when being energized, and restricting the rotary shaft when not being energized. The brake mechanism has such brake force that supports the weight of the arm part when not being energized, to retain an attitude of the arm part, and can rotate the rotary shaft by external force equal to or more than a prescribed value.SELECTED DRAWING: Figure 5【課題】電力の供給が遮断された場合に停止し、電源喪失時であっても手術を継続可能とした、安全性を向上した医療用支持アーム装置及び医療用観察装置を提供する。【解決手段】アーム部を構成する複数の関節部に、通電時に関節部の回転軸を解放し非通電時に回転軸を拘束するブレーキ機構３７０が設けられ、ブレーキ機構は、非通電時にアーム部の重さを支持してアーム部の姿勢を保持するとともに所定の値以上の外力によって回転軸が回転可能なブレーキ力を有する、医療用支持アーム装置を提供する。【選択図】図５
