A lawn mower includes a hollow shaft, a cutter blade, flaps, a belt type continuously variable transmission, and a transmission mechanism. The cutter blade extends along a horizontal line which is perpendicular to the hollow shaft. The flaps are provided for the cutter blade. Each of the flaps has a flap angle changeable along the horizontal line. A control force converter unit of the belt type continuously variable transmission converts a displacement force of the movable sheave relative to the fixed sheave in an axial direction into a control force that controls the flap angle of the flaps. The transmission mechanism is accommodated inside the hollow shaft, and transmits the control force to the flaps.
