To provide a slippage preventive body that can be removed from a mold with ease after molding and can be attached to a step tread with ease and without excess force and skill.

A bag-shaped slippage preventive body to be fitted on a pedal stop tread 4 to cover the top is formed out of a soft resin 3 at its tread, and also out of a hard resin 2 at least part of its fitting grooves 8 in which the edge of the step tread 4 are fitted and at its locking claw 10 to be locked on the edge of the step tread 4. The locking claw 10 is formed with an inclined face 7 for guiding the edge of the step tread 4 into the fitting groove 8 at fitting.