To provide a protective device of high versatility which can be easily installed onto/removed from a tool.

This protective device is for a tool 2 for a tire installing/removing device provided with at least one work slot or groove 3 composed to slide to be engaged with a circumferential edge 4 of a wheel rim C installed on the tire installing/removing device when in use. The protective device comprises a thin member 1 composed to be seated in at least part of the work slot or groove 3 to cover the part, and holding means 8a and 8b disposed between the thin member 1 and the tool 2 to removably position and hold the thin member in the work slot or groove 3.