To easily manufacture a cover cloth for feather quilts having a three- dimensional structure and to enable its automated production.

Gusset parts 15 which are formed by cutting out a flat planar sheet 1 and connecting belt-like parts 14 extending along the parting-off segments of the completed quilt over the entire surface on the cover cloth to an integrated shape, superposing two sheets thereof on each other and bonding both ends of the respective superposed belt-like parts to each other are used as a gore body 16. The cover cloth is formed by bonding the outside surfaces in the central parts of the belt-like parts of the gusset body and side materials. Accordingly, the gusset body is completely flat planar in the process of manufacture and since the entire part is integrally formed, the manufacture is easy and suitable for automation.