A clip comprises a grommet and a pin, and the grommet has a flange and leg pieces. The flange has a pair of right and left flange bodies, bridges for joining the flange bodies, and an opening portion formed at the center portion thereof. Peripheral walls of the opening portion are formed by the respective end faces of the flange bodies and the bridges, and the right and left peripheral walls formed by the end faces of the flange bodies and the front and rear peripheral walls formed by the end faces of the bridges are offset in a thickness direction, thereby establishing a positional relationship in which the right and left peripheral walls and the front and rear peripheral walls do not intersect to each other.