<p>A tractor capable of well securing heat balance in a bonnet. A radiator having an outside air suction fan is disposed forward of an engine, and the engine and the radiator are covered by the bonnet. The outside air is sucked by the outside air suction fan through a front grill part formed in the bonnet to cool the radiator. A radiator cooling air discharge port is formed in the side wall part of the bonnet so as to be opened to the rear side.</p>
