To solve the problem that strength against loads in a horizontal direction and a shelf board thickness direction is comparatively weak and stability is poor in assembling the sideboards and the shelf boards of conventional furniture such as a knock down storage shelf.

The knock down furniture is composed of vertical members and a horizontal member. A plurality of through-holes are punched in the vertical members. Metal connection fittings composed of an attachment part with attachment holes punched therein and a screw part are fitted to both the side parts of the horizontal member. The screw parts of the metal connection fittings are respectively put through the through-holes, which are punched in both the vertical members and in both the leg members of the vertical members, and fastened with nuts, so that the vertical members and the horizontal member and also the vertical members, the horizontal member, and the leg members are respectively connected and fixed.