PROBLEM TO BE SOLVED: To appropriately absorb a difference in body size of a wearer, suppress a decrease in transmission efficiency of an assist force, have good followability to the movement of the wearer, and do not generate an assist force during a walking motion. However, it provides an assist device that allows the wearer to walk comfortably. SOLUTION: A waist mounting band 5, a shoulder mounting band 3, an actuator 25, a power transmission member 21 connected to the actuator, and a pulley to support a leg side pulley 32 by transmitting a force from the power transmission member. The wearer is connected to the support portion 31Z, the leg side pulley 32 which is a pulley arranged below the pulley support portion, the two knee connecting members 22 hung on the leg side pulley, and one end of both knee connecting members. The left knee attachment band 9L attached to the left knee portion of the above, the right knee attachment band 9R connected to the other end of both knee connecting members and attached to the wearer's right knee portion, and the posture of the wearer are detected. It has a posture detection device and a control device 52 that controls an actuator based on the detected posture information of the wearer. [Selection diagram] Fig. 1【課題】軽量であり、装着者の体格差を適切に吸収してアシスト力の伝達効率の低下を抑制し、装着者の動作への追従性がよく、歩行動作時はアシスト力を発生させなくても装着者が楽に歩行することができるアシスト装置を提供する。【解決手段】腰部装着帯５と、肩部装着帯３と、アクチュエータ２５と、アクチュエータに接続された動力伝達部材２１と、動力伝達部材からの力が伝達されて脚側プーリ３２を支持するプーリ支持部３１Ｚと、プーリ支持部の下方に配置された滑車である脚側プーリ３２と、脚側プーリに掛けられた両ひざ連結部材２２と、両ひざ連結部材の一方端に接続されて装着者の左ひざ部に装着される左ひざ装着帯９Ｌと、両ひざ連結部材の他方端に接続されて装着者の右ひざ部に装着される右ひざ装着帯９Ｒと、装着者の姿勢を検出する姿勢検出装置と、検出された装着者の姿勢情報に基づいてアクチュエータを制御する制御装置５２と、を有する。【選択図】図１
