To provide a bush cutter having a constitution capable of preventing the compaction of a nut caused by relative rotation of a reaping operation safety member and a reaping blade when the member is grounded and capable of readily carrying out the attaching and detaching operation of reaping blades and change of reaping operation safety members.

In this bush cutter having a constitution comprising a power transmission shaft 4 arranged in the interior of a case part positioned at the tip part of an operation lever 2, a reaping blade 5 integrated with the power transmission shaft 4 by fastening a nut 8 to a left screw part 4B formed at the tip of the power transmission shaft and a reaping operation safety member 9 forming a protecting cover of the nut 8 arranged between the nut 8 and a lower washer 7 so as to perform fastening by the nut 8, a projecting part 10 and a recessed part 11 to be engaged with the projecting part are engaged with the upper part of the reaping operation safety part to prevent the relative rotation of the reaping operation safety member based on the power transmission shaft.