The purpose of this study is to develop the ECO-insulator, which has thermal, humidity control and fireproof performance, for another to utilize agricultural wastes: rice-straw and chaff. Firstly, material properties of this ECO-insulator were measured and next, numerical simulations using these material properties were performed and the results of this ECO-insulator were compared with cases of Glass Wool and Extruded Polystyrene. The results are as follows; 1) Thermal performance of the insulator was more than one of Giass Wool 10K. 2) The fireproof performance was equivalent to one of Quasi-noncombustible Materials. 3) Without layer of vapor-barrier, it is pcssible to stop the dew condensation in the insides of walls, because of humidity control performance of this insulator.
