To provide a work machine having a simplified construction which can perform offset work, comprises a winding transmission mechanism, and can regulate an amount of offset.SOLUTION: A work machine comprises a rotation mechanism unit comprising: a winding transmission mechanism for transmitting power to a work part； a power unit for generating power that extends and shrinks； and an arm-shaped member which can rotate with the winding transmission mechanism with power generated by the power unit around an axis extending in a first direction. The arm-shaped member is configured so that a rotation range to one side is regulated before the power unit is fully shrunk and a rotation range to the other side is regulated before the power unit is fully extended.SELECTED DRAWING: Figure 1【課題】オフセット作業が可能な作業機において、巻き掛け伝動機構を有し、かつ、オフセット量を規制することが可能なより簡易的な構成を有する作業機を提供すること。【解決手段】作業機は、動力を作業部に伝達する巻き掛け伝動機構と、伸縮する動力を生成する動力部と、第１方向に延びた軸を中心として動力部が生成する動力によって巻き掛け伝動機構とともに回動可能なアーム状部材と、を有する回動機構部を有し、アーム状部材は、動力部が縮みきる前に一方への回動範囲が規制され、動力部が伸びきる前に他方への回動範囲が規制される。【選択図】図１
