The technical result of the invention is to simplify the technology of obtaining insulin-producing cells, obtaining at least 70% of functionally active insulin-producing cells in cell culture, that underwent differentiation. The method comprises obtaining epithelial progenitor cells and their subsequent differentiation into pancreatic cells, capable to glucose-sensitive insulin secretion in which pancreatic differentiation is performed in two stages:(a) at the first stage cells are differentiated within 4-15 days in a culture medium containing at least serum of a mammal, glutamine, epidermal growth factor, transferrin, sodium selenite, retinoic acid, isoproterenol；(b) at the second stage, cells are differentiated within 4-15 days in a culture medium containing at least serum of a mammal, glutamine, epidermal growth factor, retinoic acid, nicotinamide, hepatocyte growth factor, dexamethasone；moreover, the cultivation in both stages is carried out in gas atmosphere of 5% CO2 at 37° C. Group of inventions includes cell product of insulin-producing cells of a mammal, and a method of differentiation of pancreatic epithelial progenitor cells of mammals, including humans, as well as a method for replacement therapy of diabetes mellitus using cell product.
