To produce high quality appearance interior parts, precise pattern forming or gloss reduction of three-dimensional door trim cover materials are utilized. In the preparation of formed trim cover using polyvinyl chloride (PVC), prior pattern forming on original cover material or post-pattern forming with vacuum forming dies are employed. In the latter case, the die is usually made of epoxy resin. Although vacuum holes are prepared on the resin die as necessary, the lack of uniformity in air permeability causes inferior pattern transferability.In this development, special porous ceramic die is used as die material so that trim cover material can be evenly sucked through the fine pores on its surface. As a result, a door trim forming die of superior pattern transferability has realized. The features of this- die are as follows.1) The addition of metal powder, metal fiber, and binder to the ceramic powder has achieved well balanced air permeability, compressive strength, and dimensional change rate.2) The uniform, high air permeability can produce deep and precise grain and stitching pattern (patterns) transfer with a low surface gloss rate. A work area with a stable surface quality can also be secured.3) A shorter lead time of manufacturing and lower die making cost have achieved.