A therapeutic agent for a corneal epithelial disorder, containing a miR-203 inhibitor; an agent for promoting proliferation of corneal epithelial cells, containing a miR-203 inhibitor; a liquid culture medium for use in the manufacture of a corneal epithelial sheet, containing a miR-203 inhibitor; and a method for producing a corneal epithelial sheet, including the step of culturing corneal epithelial cells using a liquid culture medium containing a miR-203 inhibitor. According to the present invention, a therapeutic agent for a corneal epithelial disorder, an agent for promoting proliferation of corneal epithelial cells, a liquid culture medium for use in the manufacture of a corneal epithelial sheet, a method for producing a corneal epithelial sheet, including the step of culturing corneal epithelial cells using the liquid culture medium, and a method for treating a corneal epithelial disorder can be provided. The present inventors have also found that not only the above effects are exhibited by inhibiting miRNA richly contained in tears, but also the agent specifically acts on eye surfaces, so that the present invention can be expected to show high safety.