For mushroom production, a large scale of culture beds was used. After production, their culture beds were disposed. Some of them were recycled to composts. However, large parts of them were not recycled. We tried to utilize the culture beds, such as bed-logs and sawdust-based cultures, for production of fuel gas by thermal gasification. In this gasification system, we have proposed the advantageous system for two stage gasification. In first stage, waste woods are carbonized and in second stage, chars are gasified with steam. In the latter stage, wood gas produced in first stage is used as fuel for gasification. We obtained the good results for production of fuel gas with higher hydrogen contents and no tar production from two stage gasification of both culture beds.