[Problem] To provide, in order to manufacture cells to transplant into patients with corneal endothelial failure, a medium used to culture corneal endothelial cells obtained from human corneal tissue and grow said cells while maintaining the morphology thereof as corneal endothelial cells. [Solution] A medium containing a conditioned medium from mesenchymal stem cells; and a method in which said medium is used to culture corneal endothelial cells.