The purpose of the present invention is to obtain an alternative to a substitute of the mucosa in the middle ear which is engrafted on the surface of the bone in the middle ear, hyperplasia of the granulation tissue and the bone and the development of the fibroblast cells in the middle ear are suppressed, and to obtain a middle ear mucosa-like cell sheet retaining cilia in the surface layer, comprising culturing nasal epithelium cells on a cell culture substrate coated with a polymer whose hydration force changes within a temperature range of 0 to 80°C, wherein the cells are cultured within a temperature range where the hydration force of the polymer is weak, and then changing the temperature to a temperature at which the hydration force is strong to recover the cultured cell sheet.
