The present invention provides a method for producing a transplant material, comprising the step of obtaining a transplant material that expresses a secretory protein by differentiating iPS cells into which a secretory protein gene has been introduced.本発明は、分泌タンパク質遺伝子を導入したiPS細胞を分化させて分泌タンパク質を発現する移植材料を得る工程を含む移植材料の製造方法を提供する。