A developing apparatus includes a developer container that stores developer, a conveyance screw including a shaft portion and a blade, a bearing portion configured to engage with an engagement portion of the shaft portion of the conveyance screw, and a magnetic seal member having a magnetic property and disposed along a peripheral surface of the shaft portion in a noncontact manner with respect to the shaft portion between the blade and the engagement portion in the rotational axis direction of the conveyance screw.