Provided is a portable brush cutter with reduced weight and size due to its simple structure with a small number of components that is capable of improving durability and the like as well as effectively suppressing torsional vibration of a transmission shaft. In the portable brush cutter, a one-way clutch to prevent generation of torsional vibration in a rotation transmission path is interposed between an output shaft and a transmission shaft, and bearings are adjacently mounted on the opposite sides of the one-way clutch.
