Lawn mower

A lawn mower comprising:

• a housing including an opened bottom;
• a rotation shaft extending in a vertical direction of the housing and including a lower end positioned within the housing;
• a cutter blade provided for the rotation shaft, and accommodated in the housing;
• a drive source configured to drive the cutter blade through the rotation shaft;
• a grass clippings container configured to store lawn grass which is cut by the cutter blade and is transported from the housing by transportation wind generated by the cutter blade;
• a flap provided for the cutter blade, the flap having a flap angle changeable along a horizontal line which is perpendicular to the rotation shaft;
• an actuator configured to control the flap angle of the flap;
• a control unit configured to control the actuator;
• a grass clippings container weight detection unit configured to detect weight of the grass clippings container;
• and
• an internal pressure detection unit configured to detect internal pressure of the housing,
• wherein the control unit is configured to:
• determine a change amount per predetermined fixed time of the weight detected by the grass clippings container weight detection unit;
• determine a change amount per a predetermined fixed time of the internal pressure detected by the internal pressure detection unit;
• and
• control the actuator to place the flap in a substantially horizontal state, in a case in which it is determined that two conditions are satisfied, the two conditions being a first condition where the change amount of the weight is below a predetermined weight change amount reference value and a second condition where the change amount of the internal pressure has reached a predetermined internal pressure change amount reference value.