A control unit of a lawn mower performs switching control for switching operation between a first control mode and a second mode. In the first control mode, during rotation of an engine at a first reference rotation speed, in the case where a change amount of rotation speed of the engine per unit time has exceeded a reference speed change amount, the rotation speed is maintained at a second reference rotation speed, and an flap angle is increased. In the second control mode, during rotation of the engine at a second reference rotation speed, in the case where an opening angle of a throttle valve has fallen below a reference opening angle, the rotation speed is maintained at the first reference rotation speed, and the flap angle is decreased. The second reference rotation speed is higher than the first reference rotation speed.
