PROBLEM TO BE SOLVED: To provide a structure enabling a rear mower bucket to be simply attached and detached from the side of a vehicle body while keeping the state in which the rear mower unit is housed in and attached to the belly part of the vehicle body.SOLUTION: The supporting mechanism of the rear mower bucket 105 freely detachable to the front part of the rear mower unit 1C arranged at the belly part of the vehicle body is constituted as follows. A bucket insertion-guiding rod 87 is protruded in the oblique front direction along a drawing rod 89 from the terminal part at the opposite side of a taking-out side at the side of the rear mower unit 1C to the vicinity of the nearly center position of the right and left of the rear mower unit 1C. An engaging metal fitting 120 is installed in the terminal part at the side opposite to the taking-out side of the rear mower bucket 105, and the engaging metal fitting 120 can be engaged by being hooked to the bucket insertion-guiding rod 87.
