< Topic >Job at the place where foothold is bad is made possible, the auxiliary tool for half-sitting posture job which can lighten the waist worker in attitude of the half-sitting posture and the load which falls on the knee is offered.SolutionsAuxiliary tool 100 for half-sitting posture job has, the thigh on left and right worker thigh supporter the below the knee on left and right of 20 of the left and right pair which is supported respectively from rear side and worker below the knee supporter outer part surface side of the knee joint on left and right of 30 of the left and right pair which is supported respectively from rear side and worker and/or on the inside surface side, restricting the operational area of crookedness of the knee joint worker, thigh supporter 20 and below the knee supporter 30 crookedness regulation section 50 of the left and right pair which time motion possibly is concatenated respectively and. Because as for worker, it is possible, to maintain the attitude which is stabilized when the operational area of crookedness of the knee joint is maintained burden of the knee and the waist lightens.< Choice figure >Drawing 1【課題】足場の悪い場所での作業を可能にし、中腰の姿勢での作業者の腰及び膝にかかる荷重を軽減することができる中腰作業用補助具を提供する。【解決手段】中腰作業用補助具100は、作業者の左右の大腿部を背面側からそれぞれ支持する左右一対の大腿支持部20と、作業者の左右の下腿部を背面側からそれぞれ支持する左右一対の下腿支持部30と、作業者の左右の膝関節の外側面側及び/又は内側面側で、作業者の膝関節の屈曲の可動域を制限して、大腿支持部20及び下腿支持部30を回動可能にそれぞれ連結する左右一対の屈曲規制部50と、を備える。作業者は、膝関節の屈曲の可動域を維持した状態で安定した姿勢を保つことができるので、膝や腰の負担が軽減する。【選択図】図1