PROBLEM TO BE SOLVED: To use the reside of Metroxylon sagu as a raw material for a medium for mushroom culture by sterilizing a large amount of a ground pulp residue, discharged in producing Metroxylon sagu starch by grinding trunk of Metroxylon sagu, by radiation. SOLUTION: A culture medium for mushroom is prepared by using the residue of Metroxylon sagu starch as a main base and the prepared medium for mushroom is sterilized by radiation or by heat treatment. Various fungi of mushrooms are inoculated to the culture medium and cultured. The residue of Metroxylon sagu starch can be directly used as it is as a mushroom medium base without a treatment such as grinding, etc. The medium base is mixed with a conventionally useful nutriment such as rice bran, bran, soybean hull, maize residue, etc., and can be used. The base is further mixed with sawdust of broad-leaved tree and needle-leaved tree, straw, etc.
