To reduce cost by a simple structure while preventing an operational failure caused by a foreign matter and the generation of rust, in a work tool attaching-detaching device applied to a work vehicle for performing civil engineering work, agricultural work and carrying work and detachably installing a work tool such as a bucket and a fork.

This work tool attaching and detaching device is composed of a body 2, the work tool 3, a wedge hole 4, a wedge body 5, an operation lever 6, a link mechanism 7, a fixed cover 8 and a movable cover 9. The fixed cover 8 capable of covering the most part of an exposure part up to the operation lever 6 from the wedge body 5 is particularly arranged in the body 2. The movable cover 9 capable of covering the residue of the exposure part when depressing and elevating the operation lever 6 is arranged on the operation lever 6.