A deep neuromuscular block (NMB) is often associated with improved surgical conditions especially in laparoscopic surgery. We previously showed that deep NMB is superior to a moderate NMB under propofol anesthesia. However, this may not apply to sevoflurane anesthesia and sevoflurane by itself produces some degree of muscle relaxation. We therefore plan to investigate the effect of deep NMB on surgical conditions under sevoflurane anesthesia maintenance.