To provide a stud locking fixture to facilitate mounting, increase a pull-off and blocking force, to simplify structure, and to prevent a stud receiving hole from being increased more than necessary.

A stud locking fixture 1 is provided with a base part 2 in which a stud receiving hole 7 to receive a stud is formed. A plurality of lock parts 9 locked at the screw of a stud 21 received in the stud receiving hole 7 are formed at the base part 2. Each of the lock parts 9 comprises an elastic arm 13 extending to the base part 2; and a lock claw 14 arranged at the tip of the elastic arm 13. A protrusion part 15 extending toward the root side of the locked stud 21 is formed. The protrusion part 15 is formed in length long enough to allow contact of it with a base part 17 on the stud root side such that when the lock tool 1 is stretched in a direction in which the locking fixture 1 is pulled out, movement of the lock claw 14 to the stud root side is limited.