A developing apparatus includes a housing; a developing roller; a seal member, and a layer thickness regulating member that contacts a circumferential surface of the developing roller via developer and regulates a thickness of a developer layer on the circumferential surface of the developing roller. The seal member has a sliding contact portion made of fiber having elasticity and sliding-contacting the circumferential surface of the developing roller. The layer thickness regulating member has one end portion that is supported by the housing and the other end portion to which a bent portion is formed to face the seal member, and the bent portion is configured to enter the sliding contact portion.