To reduce noise in a cabin by constituting a steering system corresponding to medium and large working vehicles, even in a small working vehicle limited in space, and disposing a steering unit in a position inside an engine hood or the like, away from the cabin.

Support brackets 31, 32 for supporting steering shafts 22, 24 rotatably are arranged at two parts on the cabin side and engine 5 side. The support bracket 32 is fixedly mounted to one end of a mounting flange 5a of the engine 5, and bending angles θ1, θ2, θ3, θ4 at the respective connection parts of a plurality of rotatably connected steering shafts 21, 22, 23, 24 and a power steering unit 25 are formed to be almost the same.