The present invention relates to a holding material for a catalytic converter including a catalyst carrier, a metal casing for receiving the catalyst carrier, and the holding material wound around the catalyst carrier and interposed in a gap between the catalyst carrier and the metal casing, in which the holding material includes an inorganic fiber substrate and a viscoelastic layer formed at least on a casing side surface of the inorganic fiber substrate and having a Young's modulus at 25° C. of 0.3 MPa or less.