| abstract |
An object of the present invention is to provide a developing apparatus which is less influenced by the use environment, has a high developing efficiency during long-term use, and can provide a high-quality image without image density nonuniformity. The present invention is characterized in that the magnetic toner bearing member has a work function in a specific range on its surface and the toner regulating portion for regulating the toner carried on the magnetic toner bearing member is made of a specific material at a portion in contact with the magnetic toner, The magnetic toner has an average circularity of 0.950 or more, and the magnetic toner has a surface tension index within a specific range. |