To provide a fall prevention tool for a nut, in which, each time the nut is attached to or detached from a distal end of a bolt, it is not necessary to mount the nut to the fall prevention tool, and efficiency in continuous fastening work using a plurality of nuts can be improved.

A fall prevention tool comprises: a nut inserting member 11 to which a plurality of nuts are inserted in series; a nut holder 10 including a lock mechanism 20 which is provided closer to one end of the nut inserting member, and when located at a lock position, blocks all the nuts from being removed from the nut inserting member by locking a nut in one end, and separates the nut positioned in one end from the nut inserting member when located at a save position; and an interlock member 40 which is detachably or fixedly secured in one end to the one end of the nut inserting member, includes an adsorption member 41 adsorbed to a distal end face of a male screw of a bolt in another end, inserts/moves the nut separated from the one end of the nut inserting member, and shifts the female screw of the nut to a distal end of the male screw of the bolt.