Abstract: The object of the present invention is to provide a one-part clip, in low manufacturing cost, exhibiting the excellent function of the two-piece clip and having enough mounting strength without degrading easy repetitive detachability. Hinges 50 that connect a bar portion 30 and a leg portion 40 move so as to widen each elastic portion 43 of the leg portion 40 within the inside of the mounting hole al of the body panel A when the bar portion 30 is moved axially into the inside of the leg portion 40 by forcing the head portion 20 of the clip 10 along axis of the bar portion 30. The engaging portion formed near the end of the bar portion 30 is forced into the engaging hole 42 formed at the top end portion 41 of the leg portion 40 when the bar portion moves axially. If the head portion 20 is pulled strongly to move the bar portion 30 in opposite direction, it can be removed from the body panel A without incurring any damages.