Disclosed is a molded member with a foamed body, which is foamed on the top surface sides of a first member and a second member and is prevented from leaking from between abutment surfaces of those members toward the back side. A seal piece of a required width extending in an eaves form outward over the perimeter of the outer contour edge of an airbag door is provided at the outer contour edge. When the airbag door is laid out at a door mount portion, so formed as to surround an opening formed in a base material, the seal piece is set in close contact with the outer surface of the door mount portion in such a way as to surround the opening. This prevents the foamed body, foamed on the top surface side of the base material facing the airbag door, from leaking from a clearance, produced between abutment surface of the base material and the airbag door, toward the back side.