Abstract: An aggregate with small fiber deterioration even after being held under compression under heating at about 1,000° C. for a long term, and a holding material of e.g. a catalyst carrier of a catalyst converter or a honeycomb body of DPE employing it, are provided. An inorganic short fiber aggregate for a holding material, which is an aggregate of inorganic short fibers having a chemical composition of from 74 to 86 mass % of an alumina component and from 26 to 14 mass % of a silica component and having a mineral composition of from 15 to 60 mass % of mullite, wherein the average fiber diameter of the aggregate is from 2 to 8 ?m, at least 99% (including 100%) of the number of the inorganic short fibers consists of fibers having fiber diameters of from 1.5 to 15 ?m, and the specific surface area is at most 10 m2/g.