A perfusion system is so formed that enclosed areas may be formed in the artery system related to the pancreas and the venous system related to the pancreas, respectively, by using balloon catheters, the blood inside the venous system in the enclosed area may be extracted outside the human body, and that, after injecting a pharmaceutical such as anticancer agent into the extracted blood, the extracted blood including pharmaceutical may be returned to the artery system in the enclosed area again.