To assemble and incorporate a vertical frame member and a horizontal frame member of a door frame provided with a door body to open, close, and swing freely into an integrated condition for achieving an excellent sealing property and high strength.

Protruding pieces 5c for connection arranged on the right and left sides and protruding onto a muntin 3 side are formed in both of right and left end parts of a door sill 5, and a thin neck part 5d is formed in a protruding basic end part of the protruding piece 5c for connection. A through hole 3f in which the protruding piece 5c is inserted is formed in the muntin 3, and the thinnest part 5e of the thin neck part 5d of the protruding piece for connection is positioned in the through hole 3f and is bent in the thinnest part 3e to integrate the door sill 5 and the muntin 3 mutually.