To simplify fitting and detaching of a slip preventing element against a tire capably of being used in emergency by providing a plate body hanging down fixing claws on one end and standingly provided with a pin on the upper face, and providing a connecting body connected to the plate body at the front part and penetratedly provided with a plurality of joint holes on the rear part.

This slip preventing element (a) is constituted of a plate body 3 hanging down rake-like fixing claws at the extreme end and standingly provided with a pin 2 on the upper face, a spring steel plate 6 joined with the through hole 4 on the rear end of the plate body 3, and a connecting body 9 consisting of synthetic resin plate 8 integrated with the rear end of the spring steel plate 6 and penetratedly provided with three joint holes 7 on the rear part. The elements (a) are joined with a ring-like rubber ring through the joint holes 7 at the uniformly divided points so as to constitute a slip preventing tool. The slip preventing tool is used by engagedly fitting the fixing claws 1 to the wall of a groove of the tread pattern of a tire and letting bite the fixing claws 1 in the wall of the groove. Hereby, when the grounding face is on the engagedly fitting position at engagedly fitting the element (a) to the tire, by a little moving the automobile it can be easily engagedly fitted, and hence emergent slip prevention can be executed by a simple mounting work.