An engine-driven brush cutter (100) equipped with a safety device (42) that includes an acceleration sensor unit (24) attached to a drive unit (4) in an aslant orientation such that a detection axis (DA) of the sensor unit (24) inclines by an angle (θ1) relative to the up-and-down direction (V) of the brush cutter (100). This inclined orientation of the detection axis (DA) contributes to lowering the sensitivity of the sensor unit (24) to engine vibration to which the safety device should not be sensitive so much.