PURPOSE: To obtain a substrate which is a cellular structure, having the surface composed of a carbohydrate, protein, lipid, synthetic polymer or complex compounds thereof and capable of culture with maintained highly functional expression of cultured cells for a long period by specifying pore diameter thereof.

CONSTITUTION: A substrate which is a cellular structure having the surface composed of any one or more of a carbohydrate, protein, lipid, synthetic polymer and complex compounds thereof and its pore diameter of 1.5-10 times based on that of cells having the largest average diameter in two or more kinds of cells subjected to simultaneous culturing and used for cell culture. The formation of the aforementioned substrate surface can be carried out by a method for dipping the cellular structure in a solution of the above-mentioned substances an then drying the structure or coating the cellular structure with the solution and drying the resultant substrate. In order to provide the substances for forming the substrate surface with stability, the cellular structure can be subjected to treatment with radiation, ozone, ions, chemicals, physical treatment with laser, etc., then dipped or coated or, as necessary, chemically bound to the surface by an active ester, carbodiimide, isocyanate, etc.