We studied the effect of Beriplast P membrane including MMC (2 mg/ml) on human gastric carcinoma implanted in nude mouse (OSS) as a example of a shallow but broad lesion as with an early-stage local recurrence of rectal cancer and superficial gastric cancer. As a result, the resected tumor contact Beriplast P membrane including MMC after 3 days showed continuous necrotic lesions, from 1 to 2 mm in depth. No side effect was observed in nude mice. These results indicated that Beriplast P membrane including MMC is a useful chemotherapy against local cancerous lesion.