A developing apparatus includes a roller-shaped developer carrying member, a
frame
for holding the developer carrying member, and a magnetic seal member for preventing
leakage of a developer from an end of the developer carrying member in a longitudinal
direction of the developer carrying member. The magnetic seal member includes an
arcuate magnet portion to be disposed along a circumferential direction of the
developer carrying member, and a non-arcuate portion which extends from an end,
in the circumferential direction, of the magnet portion away from a peripheral
surface of the developer carrying member and is different in material from the
magnet portion.
