The present invention can speedily and easily perform the maintenance or the like of hydraulic equipment and the like. Accordingly, in the present invention, in a tractor in which a prime mover portion is arranged on a front portion of a machine body, a driving portion is arranged behind the prime mover portion, a transmission portion is arranged below a driver's seat which is formed in the driving portion, left-side and right-side rear wheels are mounted on the transmission portion by way of a rear axle case, and a cover body is extended over the driving portion, the transmission portion and the left-side and right-side rear wheels, the cover body constitutes a step portion of the driving portion and, the cover body covers the transmission portion from above and covers the left-side and right-side rear wheels from the front side and above, the cover body is formed of a plurality of split-portions, and at least the split-portion which covers the transmission portion from above is detachably formed.