PROBLEM TO BE SOLVED: To provide methods of producing a practical pseudoislet suitable for medical transplantation, and the like by the high efficient induce differentiation of a pluripotent cell into a pancreatic islet progenitor cell or an islet cell with simple operations.SOLUTION: A production method of a pseudoislet comprises: seeding 1500-5000 cells/well of pluripotent cells in a cell culture well and producing a pluripotent cell aggregate with a given size； and culturing the aggregate in non-adhesive conditions in the cell culture well and differentiating it into a cell containing a pancreatic islet progenitor cell or an islet cell.SELECTED DRAWING: Figure 6【課題】簡易な操作で、多能性細胞を、膵島前駆細胞または膵島細胞へと高効率で分化誘導させ、移植医療などに適した実用的な疑似膵島を製造する方法を提供すること。【解決手段】細胞培養ウェル内に、1500個～5000個/ウェルの多能性細胞を播種し、前記多能性細胞の所定サイズの凝集体を作製する工程と、前記凝集体を前記細胞培養ウェル内で非接着状態で培養し、膵島前駆細胞または膵島細胞を含む細胞へと分化させる工程と、を含む、疑似膵島の製造方法。【選択図】図６
