Abstract: [Object] Provided is an aqueous treatment agent having a satisfactory environmental safety and aqueous solution stability, with which satisfactory surface modification properties are obtained for various molded articles and the like. [Solving Means] An aqueous treatment agent including an imide group-containing compound derived from an imide group-containing compound obtained by partially hydrolyzing a polyimide molded article; a fluororesin-containing aqueous dispersion liquid; and an amine compound, in which an incorporation amount of a fluororesin included in the fluororesin-containing aqueous dispersion liquid is adjusted to a value within the range of 0.1 to 10,000 parts by weight, in terms of solid content, with respect to 100 parts by weight of an imide group-containing compound included in the imide group-containing compound.