Front and rear support members which support a deflector plate configured to project upward above a front header when a roof is open include respective joint portions where respective lower portions thereof are joined to each other. The deflector plate includes deflector lower portions which project downward at respective positions where the deflector lower portions do not interfere with the joint portions of the front and rear support members when the deflector plate is located at a lowermost position. An elevating mechanism (springs, groove portions pins) which is configured to elevate or lower the deflector plate relative to the front and rear support members is provided between the deflector lower portions and the front or rear support members.