Provided is a method for the stable maintenance and culture of hepatoblast like cells generated during the course of differentiation induction from polyfunctional stem cells to hepatocytes. The present invention also provides a culture product obtained by the culture method. The stable maintenance and culture of hepatoblast like cells is possible by bringing hepatoblast like cells into contact with laminin. By means of this method that uses laminin it is possible for the first time to culture maintain and propagate hepatoblast like cells. By maintaining hepatoblast like cells the desired mature cells such as mature hepatocytes or bile duct epithelial cells can be created in a short amount of time and made available at the desired time. Moreover differentiation induction of the resulting cultured hepatoblast like cells to mature hepatocytes or mature bile duct cells and mature bile duct epithelial cells is possible. Due to this configuration this substantially pure culture product can be used as a transplant composition for the regeneration of hepatocytes and/or bile duct epithelial cells.