An objective of the present invention is to provide a method for reducing surface free energy of an organic solvent and of a mixed solution of water and a water-miscible organic solvent, a composition which has a reduced surface free energy of an organic solvent and of a mixed solution of water and a water-miscible organic solvent and which has high environmental suitability and safety to a living body, and a wet wiper and an antiseptic solution which contains the composition The method for reducing surface free energy of an organic solvent or a mixed solvent of water and a water-miscible solvent according to the present invention is characterized in comprising the step of adding surfactin or a salt thereof to the organic solvent or mixed solvent.