A lawn mower (10) includes a drive source (15) for driving a cutter blade (14), flaps (52), a grass clippings container (22), a grass clippings container weight detection unit (113), a travel distance detection unit (131), and a control unit (117). The control unit (117) determines a change amount (Wa) of weight (Wr) of the grass clippings container (22) detected by the grass clippings container weight detection unit (113) over the elapsed time period from the time when detection of travel distance (Lr) of the lawn mower (10) is started by the travel distance detection unit (131) to the time when travel of predetermined distance (Ls) is completed, and implements control in a manner that the rotation speed (Ner) of the drive source (15) and the flap angle (¸r) of the flaps (52) are adjusted in accordance with the change amount (Wa) of the weight (Wr).
