A developing device includes: a developing roller; a magnet provided in
the roller and having a plurality of local maximum magnetic flux density
positions on the peripheral surface of the magnet; a developing container
supporting the roller; a seal member for preventing a developer from
leaking out of the container; and a developer regulating member having a
scraping member abutting the roller for collecting the developer on the
surface of the roller toward the inside of the container in the axial
direction. When viewing the developing device in the axial direction, the
scraping member abuts the roller between a first position where the
surface of the roller is crossed by a line which connects the supporting
portion and a local maximum magnetic flux density position that is
nearest to the supporting portion, and a second position where the roller
develops the latent image.