An object of the present invention is to provide a pancreatic islet transplantation technique that enables increase of graft survival rate of pancreatic islets after pancreatic islet transplantation, to maintain survival of pancreatic islets, and to reduce the number of transplanted pancreatic islets required for normalizing blood glucose level. When performing pancreatic islet transplantation, by transplanting pancreatic islets and adipose tissue-derived stem cells together, it is possible to significantly improve graft survival rate of transplanted pancreatic islets, and reduce by half the number of transplanted pancreatic islets required for normalizing blood glucose level.
