To obtain the subject composition enabling easy and sure dry-wiping of residues on the surface of a treating object with an organic solvent by using a fluoroalkylsilane, water, a hydrophilic organic solvent and a specific compound as essential components.

This agent is preferably composed of (A) a 1st liquid containing (i) 0.05-10wt.% of a fluoroalkylsilane and (B) a 2nd liquid containing (ii) 0.1-50wt.% of an acid and (iii) 0.1-40wt.% of water. The component A and/or the component B contain (C) a hydrophilic organic solvent and (D) a compound having a boiling point higher than that of the component C. The component D is preferably a compound capable of dissolving the unreacted component (i) and/or a hydrolysis product of the component (i), especially a silicone oil, concretely a cyclic polydimethylsiloxane and/or an acyclic polydimethylsiloxane having a viscosity of ≤1,000cst.