A lawn mower includes a drive source for driving a cutter blade through a rotation shaft, a flap provided for the cutter blade in a manner that the flaps have a flap angle changeable along a horizontal line which is perpendicular to the rotation shaft, an actuator for controlling the flap angle of the flaps, a control unit for controlling the actuator, and a blade switching unit for switching the cutter blade between an operation state and a stop state. When the control unit determines that a stop switch signal has been received from the blade switching unit, the control unit controls the actuator to increase the flap angle of the flaps.
