The present invention aims to provide a method of efficiently producing corneal endothelial cells, particularly from corneal stroma or iPS cell-derived neural crest stem cells, a method of producing corneal endothelial cells stably in a large amount by inducing more efficient differentiation of stem cells into corneal endothelial cells, and a medicament containing corneal endothelial cells. A method of inducing differentiation of stem cells into corneal endothelial cells, which includes a step of culturing the stem cells in a differentiation induction medium containing a GSK3 inhibitor (preferably a GSK3² inhibitor) and retinoic acid, preferably the differentiation induction medium further containing at least one kind selected from the group consisting of TGFb2, insulin and a ROCK inhibitor, and the like.