Uneven distribution of grass clippings in a grass clippings receptacle of a lawn mower can be minimized. A lawn mower (1), comprises: a work unit (5) including a housing (21) having a downward-facing opening and a cutter blade (22) rotatably provided in the housing such that when rotated, the cutter blade cuts grass and generates a transport air flow flowing from the opening of the housing to inside； a grass clippings receptacle (6) configured to receive mowed grass clippings； a grass clippings transport passage (38) connecting an interior of the housing with the grass clippings receptacle； a shutter device (40) including a shutter (41) configured to open and close the grass clippings transport passage and an actuator (42) configured to open/close-drive the shutter； a controller (50) configured to control the shutter device； and a speed sensor (66) for detecting a travel speed of the lawn mower, wherein the controller is configured to open/close-control the shutter device based on the travel speed.
