An image carrying member unit (40a - 40d) comprising: an image carrying member (1a - 1d) on which an electrostatic latent image is formed, the image carrying member (1a - 1d) being rotatable; a charging device (2a - 2d) including: a charging roller which electrostatically charges the image carrying member (1a - 1d) while rotating in contact with a circumferential surface of the image carrying member (1a - 1d) by following the image carrying member (1a - 1d) as the image carrying member (1a - 1d) rotates; a cleaning member which cleans the charging roller while rotating in contact with a circumferential surface of the charging roller; and a pair of first and second bearing members (92a, 92b) which rotatably supports opposite end parts of the cleaning member and the charging roller with a predetermined interval between the cleaning member and the charging roller; and the image carrying member unit further comprises a pair of first and second supporting frames (51a, 51b) on each of which an image carrying member bearing is formed, the image carrying member bearings rotatably supporting opposite end parts of the image carrying member (1a-1d), wherein in one end part of the image carrying member (1a - 1d), an output-side gear is provided_which transmits the rotation driving force of the image carrying member(1a - 1d) to the cleaning member, in one end part of a rotary shaft of the cleaning member, an input-side gear coupled to the output-side gear is provided, characterised in that the charging device (2a-2d) further includes a pair of biasing members which respectively bias the pair of first and second bearing members (92a, 92b) in a direction approaching the image carrying member (1a- Id); and in that the image carrying member bearing, provided on the end side where the output side gear is provided, and a first cleaning member bearing which rotatably supports the one end part of the rotary shaft of the cleaning member where the input-side gear is provided are integrally formed with said first supporting frame supporting the one end part of the image carrying member (1a - 1d) where the output-side gear is provided. an image carrying member (1a - 1d) on which an electrostatic latent image is formed, the image carrying member (1a - 1d) being rotatable; a charging device (2a - 2d) including: a charging roller which electrostatically charges the image carrying member (1a - 1d) while rotating in contact with a circumferential surface of the image carrying member (1a - 1d) by following the image carrying member (1a - 1d) as the image carrying member (1a - 1d) rotates; a cleaning member which cleans the charging roller while rotating in contact with a circumferential surface of the charging roller; and a pair of first and second bearing members (92a, 92b) which rotatably supports opposite end parts of the cleaning member and the charging roller with a predetermined interval between the cleaning member and the charging roller; and the image carrying member unit further comprises a charging roller which electrostatically charges the image carrying member (1a - 1d) while rotating in contact with a circumferential surface of the image carrying member (1a - 1d) by following the image carrying member (1a - 1d) as the image carrying member (1a - 1d) rotates; a cleaning member which cleans the charging roller while rotating in contact with a circumferential surface of the charging roller; and a pair of first and second bearing members (92a, 92b) which rotatably supports opposite end parts of the cleaning member and the charging roller with a predetermined interval between the cleaning member and the charging roller; and the image carrying member unit further comprises a pair of first and second supporting frames (51a, 51b) on each of which an image carrying member bearing is formed, the image carrying member bearings rotatably supporting opposite end parts of the image carrying member (1a-1d), wherein in one end part of the image carrying member (1a - 1d), an output-side gear is provided_which transmits the rotation driving force of the image carrying member(1a - 1d) to the cleaning member, in one end part of a rotary shaft of the cleaning member, an input-side gear coupled to the output-side gear is provided, characterised in that the charging device (2a-2d) further includes a pair of biasing members which respectively bias the pair of first and second bearing members (92a, 92b) in a direction approaching the image carrying member (1a- Id); and in that the image carrying member bearing, provided on the end side where the output side gear is provided, and a first cleaning member bearing which rotatably supports the one end part of the rotary shaft of the cleaning member where the input-side gear is provided are integrally formed with said first supporting frame supporting the one end part of the image carrying member (1a - 1d) where the output-side gear is provided.