Abstract: Corrugated cardboard is molded into a desired shape for use in interior trim, such as for use in lining the ceiling of an automobile. The molded corrugated cardboard is obtained by applying a hot-melt adhesive onto all or at least a portion of a side of a base layer of, for example, resin felt or non-woven fabric. The base layer is then applied to a plate-like corrugated cardboard layer such that the hot melt adhesive is between the two layers. The corrugated cardboard and base layers are then molded together. The base layer may be put on only a portion of the cardboard layer where molding is apt to cause wrinkling or rupture of the cardboard layer, or the base layer may be applied to an entire surface of the corrugated cardboard layer. Even if the corrugated cardboard wrinkles or ruptures during molding, the wrinkle or rupture is filled by lofting of the base layer which is simultaneously molded in a superimposed state on the corrugated cardboard.