To further facilitate an assembling work of an instrument panel to a vehicle body, when providing a feeder line of an antenna extended from an internal part side of the instrument panel toward a space between a side edge part of the instrument panel and a vehicle body side part adjacent to the outside of the side edge part.

In this structure, the feeder line 17 of the antenna which extends toward the space between the side edge part 13a of the instrument panel 13 and a vehicle body side part 4 and has the extension end part 17a locked on the vehicle body side part 4 is provided. A temporary projection 37 which projects upward from the side edge part 13a of the instrument panel 13 and temporarily fastens the extension end part 17a of the feeder line 17 to the vehicle body side part 4 before locking the extension end part 17a on the vehicle body side part 4 is provided. When a garnish 31 is moved downward from the above of the locking part 34 to lock a lower end edge part of the garnish 31 on the locking part 34, the temporary projection 37 guides the lower end edge part of the garnish 31 toward the locking part 34.