A clip mounting seat includes a mounting base (30) having a mounting hole (38) and a mounting base-side insertion opening (22) that is included at a part of a hole edge (38F) of the mounting hole (38), and a wall (40) extending downward from the outer edge (39) of the mounting base (30) and including an insertion-side wall (45) having a wall-side insertion hole (44) communicated with the mountingbase-side insertion opening (33), and a guide member (50) configured to guide the clip in the insertion direction when the clip is inserted and having a width (W5) that is greater than an opening width (W3) of the mounting base-side insertion opening (33). The clip can be mounted on the clip mounting seat with a correct posture and the mounted clip is less likely to be detached from the clip mounting seat.