PURPOSE: To obtain the subject substrate, capable of exhibiting high effects on expression of differentiating function of cells, useful for culturing nerve system cells, mammary gland cells, etc., and capable of maintaining cell function by subjecting polysaccharides having sulfone groups to low-temperature plasma treatment.

CONSTITUTION: The objective substrate obtained by subjecting polysaccharides having sulfone groups to low-temperature plasma treatment. Furthermore, a composition composed of gelatin or a composition composed of polysaccharides having amino groups derivatives is preferably used in addition to the aforementioned polysaccharides and heparin, heparan sulfate, etc., are used as the above-mentioned polysaccharides.