A mower unit comprising: a blade (22R,22C,22L) rotatably driven about a rotational axis to be able to cut grass on the ground surface; a housing covering the blade and having a lower face thereof opened; a water feeding section provided outside the housing; a water discharging section provided inside the housing for discharging cleaning water fed to the water feeding section; and a water feeding pipe connected to/between the water feeding section and the water discharging section; wherein the water discharging section is configured to discharge water toward an inner wall face of the housing; wherein inside the housing, there is provided a vertical wall portion having an arcuate shape along an outer shape of a rotational trajectory of the blade; wherein the water discharging section is provided at a portion located in a space formed between the vertical wall portion and a rear side wall of the housing located on a side opposite a side where the blade (21R, 22C, 22L) is located relative to the vertical wall portion; wherein the water feeding pipe includes a main water feeding pipe connected to the water feeding section and a branch water feeding pipe branching from the main water feeding pipe and connected to the water discharging section; wherein the branch water feeding pipe is disposed in the space; wherein the water discharging section is fitted in a through hole in the vertical wall portion; and wherein the water feeding section is provided upwardly of the housing characterized in that, the water feeding section is provided on a side in the width direction of the housing; and in that in an outer wall face of the housing, there is provided a protection portion for protecting the water feeding section. a blade (22R,22C,22L) rotatably driven about a rotational axis to be able to cut grass on the ground surface; a housing covering the blade and having a lower face thereof opened; a water feeding section provided outside the housing; a water discharging section provided inside the housing for discharging cleaning water fed to the water feeding section; and a water feeding pipe connected to/between the water feeding section and the water discharging section; wherein the water discharging section is configured to discharge water toward an inner wall face of the housing; wherein inside the housing, there is provided a vertical wall portion having an arcuate shape along an outer shape of a rotational trajectory of the blade; wherein the water discharging section is provided at a portion located in a space formed between the vertical wall portion and a rear side wall of the housing located on a side opposite a side where the blade (21R, 22C, 22L) is located relative to the vertical wall portion; wherein the water feeding pipe includes a main water feeding pipe connected to the water feeding section and a branch water feeding pipe branching from the main water feeding pipe and connected to the water discharging section; wherein the branch water feeding pipe is disposed in the space; wherein the water discharging section is fitted in a through hole in the vertical wall portion; and wherein the water feeding section is provided upwardly of the housing characterized in that, the water feeding section is provided on a side in the width direction of the housing; and in that in an outer wall face of the housing, there is provided a protection portion for protecting the water feeding section.