Developing Apparatus, Process Cartridge and Image Forming Apparatus

A developing apparatus comprising:

• a housing having an opening;
• a developing roller that is arranged so that a part of a circumferential surface of the developing roller is opposed to the opening of the housing, is rotatably supported to the housing and carries developer on the circumferential surface of the developing roller;
• a seal member that is fixed to the housing to be opposed to the developing roller in both end portions of the opening in a rotational axis line of the developing roller and sliding-contacts the circumferential surface of the developing roller, and
• a layer thickness regulating member that contacts the circumferential surface of the developing roller via developer and regulates a thickness of a developer layer on the circumferential surface of the developing roller,
• wherein
• the seal member has a sliding contact portion made of fiber having elasticity and sliding-contacting the circumferential surface of the developing roller,
• wherein
• 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
• wherein
• the bent portion is configured to enter the sliding contact portion.