To provide a very simple and low-cost method for producing an excipient carbonized material with a strong tissue which has a lightweight and flexible porous fibrous structure, having good workability and reactivity and usable for a variety of applications, and which offers excellent carbon characteristics.

A porous structure material consisting of an intertwined combination of cellulose-based single fibers in twisted, waved, and crimped shapes is heated in a non-oxidizing atmosphere without any modification to the shapes while no binder is added so that a carbonization burning treatment is carried out. The treatment generates carbonization-contraction action which strengthens the intertwined combination between the single fibers so that the tissue is made stable and strong.