It is intended to provide a transplantation material applicable to ocular surface diseases with a need for ectocornea transplantation (i.e., an ectocornea-like sheet). Oral mucosal epithelial cells are inoculated onto an amnion and then cultured in the coexistence of supporter cells. When a layered structure of the oral mucosal epithelial cells is formed, the outermost layer is brought into contact with air, thereby inducing differentiation. Thus, an ectocornea-like sheet having an oral mucosal epithelial cell layer on the amnion is obtained.
