A cover having a side skirt and an upper face part covers a pulley provided to a mower deck. A latch mechanism removably attaches the cover to a top plate of the mower deck using an elastic deformation of the cover. The latch mechanism includes a first bracket forming a first opening, and a second bracket which is provided to the top plate so as to oppose to the first bracket via the pulley, and forms at least one second opening, a first projection provided to the side skirt of the cover, and for engaging with the first opening when attaching the cover, and at least one second projection provided to the side skirt of the cover, and for engaging with the second opening when attaching the cover.
