Disclosed is a surface-treated fine particle which is surface-treated by a simple process while being precisely controlled in the degree of the surface treatment. Also disclosed are a surface-treating apparatus and a method for surface-treating fine particles. Specifically disclosed is a surface-treating apparatus for treating the surface of a fine particle (1), and this apparatus comprises a container (2) for holding the fine particle (1), a chamber (3) for housing the container (2), a heating mechanism (4) for heating the fine particle (1) held in the container (2), and a gas-introducing mechanism for introducing a gas into the chamber (3).
