A 71-year-old woman had an episode of syncope due to hypoglycemia of 27 mg/dl. She was diagnosed with insulinoma and scheduled for laparoscopic enucleation along with the use of an artificial endocrine pancreas (STG-22, Nikkiso Co., Ltd., Tokyo, Japan). Anesthesia was maintained with sevoflurane and remifentanil. Her blood glucose level was controlled using the artificial endocrine pancreas, which enabled continuous blood glucose monitoring and computer-operated glucose and insulin infusion to maintain the blood glucose level at a steady state. The target concentration of blood glucose was set at 80-120 mg/dl during surgery. Until removal of the tumor, the blood glucose level was kept at around 80-100 mg/dl. After removal of the tumor, the blood glucose level gradually increased, but it was kept in the normal range by the artificial endocrine pancreas. The artificial endocrine pancreas was useful to monitor and maintain blood glucose levels during and after the removal of insulinoma, without any hyper- or hypoglycemia.