A grass cutter is provided with a mower and a duct. The mower includes a rotary blade which cuts grass by being driven to rotate, a mower deck which houses the rotary blade, and a fan which is arranged above the mower deck and generates carrier air. The duct includes a duct body which communicates with the mower deck and extends in a conveyance direction of grass clippings cut by the rotary blade, and an opening which is configured to allow carrier air generated by the fan to be introduced into the duct body.