Uneven distribution of grass clippings in a grass clippings receptacle of a lawn mower can be minimized. A lawn mower includes: a work unit including a housing having a downward-facing opening and a cutter blade rotatably provided in the housing such that the cutter blade cuts grass and generates a transport air flow flowing from the opening of the housing to inside; a grass clippings receptacle configured to receive mowed grass clippings; a grass clippings transport passage connecting an interior of the housing with the grass clippings receptacle; a shutter device including a shutter configured to open and close the grass clippings transport passage and an actuator configured to open/close-drive the shutter; a controller configured to control the shutter device; and a speed sensor for detecting a travel speed of the lawn mower, wherein the controller is configured to open/dose-control the shutter device based on the travel speed.