A roof panel made of resin has lower flange portions that are bent toward a vehicle lower side from vehicle side end portions of a upper surface portion. Outer panels that structure roof side rails have groove portions that are concave and are formed along a vehicle longitudinal direction at vehicle transverse direction inner sides of curved surface portions, and inner side flange portions that are formed at final end portions that are further toward vehicle transverse direction inner sides than the groove portions. In a state in which the lower flange portions are disposed within the groove portions of the outer panels, the inner side flange portions of the outer panels and an inner surface of the upper surface portion of the roof panel are joined by an adhesive.