a developing apparatus comprises : a housing having an opening that opens towards an image carrier on which an electrostatic latent image is formed , and a developer storing unit in which a developer is stored ; a developer carrier that carries the developer stored in the developer storing unit and transports the developer to a developing region in opposition to the image carrier ; a partitioning frame arranged in a groove formed between the developer carrier and the developer storing unit of the housing , that is provided with a connecting hole which enables connect between the developer storing unit and the opening ; a partition arranged on a side surface of the partitioning frame ; and a closely contact section that causes the partitioning frame to closely contact to the groove .