To prevent an insert clip from being released from a lock piece and make the fitting/removing action of a fitted component easily and reliably by forming release stop pieces into a slender piece shape having lock lugs on one side, and connecting them to the insides of leg pieces at both the upper and lower ends.

The right and left release stop pieces 3 locking a lock piece Sa are connected to the insides of leg pieces 2 at both the upper and lower ends. When the leg pieces 2 are warped inward in contact with the inner periphery of a clip fitting hole Pa, the right and left release stop pieces 3 are moved in the approaching direction. Lock lugs 3a provided on the inside of the release stop pieces 3 are also moved in the approaching direction, and the lock lugs 3a are not released from the coupling hole Sb of the lock piece Sa. When a fitted component S is removed, no unreasonable force is applied to an insert clip 1, thus the insert clip 1 is prevented from being broken or being released from the lock piece Sa of the fitted component S, and the fitted component S can be fitted or removed easily and reliably.