Rice husk, which is a typical agricultural by-product, was treated by a biomass utilization process to obtain biofuel, such as bioethanol, and biochemicals, such as furfural. Steam-explosion treatment was employed as the first step of the process. By this treatment, deconformation of the structure of rice husk and hydrolysis of hemicellulose in the rice husk occurred, simultaneously. The exploded solid product was used as the feedstock of bioethanol after separating water-soluble products. The cellulose existed in the exploded solid could be decomposed into sugars by an enzymatic reaction. On the other hand, the water-soluble products obtained in the steam-explosion contained C5 sugars. The water soluble products were fed into a hydrothermal membrane reactor in which hydrothermal reaction and pervaporation occur simultaneously to produce furfural (hydrothermal reactive pervaporation). In this presentation, some results of the steam-explosion treatment of rice husk followed by the enzymatic reaction to obtain glucose and the hydrothermal reactive pervaporation to obtain furfural are shown. Also, the total design of the proposed process is examined.