To provide: metal-containing fine particles from which the metallic component (e.g., magnetic-material ingredient) is less apt to be eluted; fine high-molecular particles useful for producing the metal-containing fine particles; and a method for producing these.

The metal-containing fine particles comprise fine metal particles and a carbonized structure in which the metal particles are dispersed. The fine high-molecular particles are obtained by (a) conducting an emulsion polymerization reaction using a polymerizable monomer containing 1% of acrylic acid and/or methacrylic acid and an emulsifying agent, and (b) mixing fine polymer particles obtained by the emulsion polymerization reaction with a salt of a metal having a valence of 2 or higher in a given pH range to conduct ion exchange between carboxy groups contained in the fine polymer particles and metal ions in the metal salt.