To provide an aqueous composition for anti-fogging and/or anti-fouling processing with multi-functions such as detergency, anti-fogging nature, stain-resistance, anti-static properties, and hygroscopicity, and to provide a substrate where the aqueous composition is impregnated or coated.

The aqueous composition for anti-fogging and/or anti-fouling processing includes: a non-cyclic guanidine compound containing a specific guanidine backbone shown by formula (1); at least one carboxy compound selected from an organic carboxylic acid, an acid anhydride, a metal salt, and an ester thereof; and a hydrophilic porous inorganic fine particles, in an aqueous liquid.