To provide a covering apparatus for an agricultural machine for preventing scattering soil tilled by a tilling rotor off a covering member irrespectively of the vertical position of the tilling rotor.

The covering apparatus 50 includes a swing arm part 51 functioning to vertically move a ceiling side cover 25 covering the upper space of a ceiling treatment rotor 24 supported in a vertically movable manner. The swing arm part 51 constitutes a link mechanism with upper link members 52 vertically spaced from each other and a lower link member longer than the upper link member 52. The lower link member is a 2nd power transmission case 26b supporting the ceiling treatment rotor 24. The upper link members 52 are pivotally joined between a tilling side cover 35 covering a pretreatment section and the ceiling side cover 25. The swing arm part 51 functions to turn the ceiling side cover 25 along the outer circumference of the ceiling treatment rotor 24 while keeping the cover 25 in nearly the identical posture in such a way that the upper link members 52 swing vertically via the ceiling side cover 25 when the 2nd power transmission case 26b swings vertically.