To prevent electrolytic corrosion, to distribute a shock load of side collision, and to secure the attaching strength of carrier brackets 7 in a case a roof panel 2 is made of an aluminum alloy and the carrier brackets 7 are arranged on a roof.

Roof reinforcements 4B-4D extending in the vehicle width direction are arranged in at least 3 positions of a position corresponding to a B pillar 5 and both front and rear positions embracing it, and attaching holes 21 are arranged in flanges 11a, 12a of side rails 1 in the positions corresponding to the respective reinforcements 4B, 4D on both front and rear sides to attach the carrier brackets 7.