PURPOSE: To obtain a toner contg. a magnetic substance with improved dispersibility for developing an electric latent image or a magnetic latent image by suspension-polymerizing a monomer contg. dispersed magnetic powder treated with a reactive silane in an aqueous medium.

CONSTITUTION: Magnetic powder treated with a reactive silane such as vinyltrimethoxysilane is dispersed in a monomer such as styrene. A polymn. initiator, etc. are added to the monomer contg. the magnetic powder, and they are added to a medium such as water, agitated, and subjected to suspension polymn. The reaction product is dried to obtain a toner. The magnetic substance is uniformly dispersed, and a free magnetic substance exists scarcely in the toner. When this toner is used in a developer, a clear image free from fog is obtd.