PURPOSE: To reduce the number of parts and simplify assembly process by integratedly forming a hook section where a molding is fitted.

CONSTITUTION: A resin roof panel 1 in which a drip 3 and a hook section 7 are molded integratedly prevents water from intruding inside by tightening and fixing it to the side roof rail outer 11a of a side roof rail 11 through a sealing material 14 using a bolt 16 and a nut 18, inserting a sealing washer 20 between the bolt 16 and the roof panel 1 and between the nut 18 and the side roof rail inner 11b, and applying a sealing material 22 between the tip of the bolt 16 and the nut. After the roof panel 1 that is fixed to the side roof rail outer 11a is coated with paint together with a car body 5, it is inserted and fixed to the hook section 7 in which a drip molding 9 is formed on the tip of the drip 3.