To obtain a protease inhibitor manifesting excellent activities for improvement and prevention of not only contact dermatitis having an observed activity change in plasmin, psoriasis, pemphigus vulgaris, congenital chicken pox or the like, and various skin diseases accompanying rough skin, but also the rough skin and chap skin or the like of a normal subject.

This protease inhibitor contains a solvent extract of Carthamus tinctorius L. belonging to the genus Carthamus of the family Compositae as an active ingredient. The formulated proportion of the solvent extract is 0.005-20.0 wt.%.