To provide the attaching part structure of a sealing member by which a sealing property is not impaired even in a state that the sealing property is deteriorated because the uneven abutting of a shaft on a lip part is caused due to the occurrence of runout when the shaft is rotated.

The attaching part structure of the sealing member is provided with a casing 4 to store developer 11, the shaft 1a housed in the casing 4 and freely rotatably supported by a bearing 3, and the sealing member 2 brought into close contact with a shaft 1 by keeping a specified bite amount so as to prevent the developer 11 from infiltrating to the bearing 3, and the shaft 1a, the bearing 3, and the casing 4 are fixed so as to keep a solid positional relation with each other, and the bearing 3 and the sealing member 2 are held by the bearing via a sponge 6.