A metal bracket (50) is mounted on the outside surface that faces outside of the passenger compartment in the lateral direction of the vehicle of an upper end (46C) of a center pillar garnish (36). When an air bag (20) is deployed, bent parts (74B) of the wings of the bracket (50) come into contact with a seat part (88) of a pillar inner panel (38) and the a portion of the expansion force is transferred. As the air bag (20) continues to expand, the bracket (50) rotates about the base of an upper inclined part (72C), and the bent parts 74B rotate toward the outside in the vehicle width direction. Because the lower edges (74C) of the wings (74) come into contact with the pillar inner panel (38), the expansion force is transferred to the pillar inner panel 38.