To provide a screw bush mounting implement by means of which, when a bolt is removed after completion of mounting a screw bush to a mold segment, the screw bush does not loosen and a shortage of screwing does not occur.

A screw bush mounting implement for mounting a screw bush into a hole before mounting formed in a screw bush mounting object material by using a bolt, includes: an operation part in which a female screw part to be engaged with a bolt is formed; and an insertion part protruded in an axial direction from the operation part and inserted into an entrance of the hole before mounting. The insertion part is inserted into a spot-faced part formed at the entrance of the hole before mounting.