Recently, regenerative therapy with tissue-engineered epithelial cell sheets has been performed for treating ocular surface disease. It would be required to develop the validation method for these cell sheets to standardize and spread the regenerative therapy. In the present study, we developed a validation system for cultivated epithelial cell sheets. Human limbal epithelial cells and human oral mucosal epithelial cells were cultured with 3T3 feeder layer cells on temperature-responsive culture inserts for three different culture periods, and subjected to cell sheet harvest and validation. Epithelial cells cultured for a short period were not successfully harvested as intact contiguous cell sheets. On the other hand, total cell number and viability of epithelial cell sheets harvested after prolonged culture period decreased. Further, these cells also lost epithelial barrier function. These results showed the potential effectiveness of the proposed validation system that can evaluate fabricated cell sheets before transplantation.