To form a division edge line between an opening and a cover body to have a clear straight line shape without causing peeling and steps like conventional cases and prevent the rubbing of a cover body side skin material and an interior material side skin material, even when the cover body side skin material and the interior material side skin material are stretched on a cabin side surface part of the cover body and an opening part peripheral part of an interior material, respectively.

The opening 3 is formed on a dash side trim 1 as the interior material, and is constituted so as to be openable/closable by the cover body 4. A cover body side projecting part 4a is formed on the outer peripheral end part on the cabin side surface of the cover body 4, and the cover body side skin material 6 is stretched inside the cabin side surface of the cover body 4 surrounded by the cover body side projecting part 4a.