An image forming apparatus, comprising: an image forming section configured to form an image on an image carrier ; a transfer roller configured to transfer the image formed on the image carrier to an image receiving medium (S); a support body configured to support the image carrier in a main body opposite to the transfer roller ; a holding member arranged in the support body to hold two end parts of the transfer roller and having a conductive member that makes electrical contact with the transfer roller when the transfer roller is mounted in the holding member ; and a power supply section configured to apply transfer bias to the image carrier and to the transfer roller through the conductive member ; the transfer roller includes a rotation shaft and a bearing supporting two end parts of the rotation shaft, and the bearing is in electrical contact with the conductive member when the bearing is mounted in the holding member ; the holding member comprises a U-shaped holding arm for holding the bearing , characterized in that : the conductive member comprises a linear U-shaped conductive spring mounted in the holding arm , two ends of the conductive member form curvature parts that protrude in the direction of the bearing towards the inside of the holding arm , a circle shaped twisted part is formed at the center part of the conductive member , the conductive member having a spring force in a direction towards the inside of the holding arm through the twisted part , and part of the linear spring is in electrical contact with the bearing of the transfer roller when the bearing is held by the holding arm . an image forming section configured to form an image on an image carrier ; a transfer roller configured to transfer the image formed on the image carrier to an image receiving medium (S); a support body configured to support the image carrier in a main body opposite to the transfer roller ; a holding member arranged in the support body to hold two end parts of the transfer roller and having a conductive member that makes electrical contact with the transfer roller when the transfer roller is mounted in the holding member ; and a power supply section configured to apply transfer bias to the image carrier and to the transfer roller through the conductive member ; the transfer roller includes a rotation shaft and a bearing supporting two end parts of the rotation shaft, and the bearing is in electrical contact with the conductive member when the bearing is mounted in the holding member ; the holding member comprises a U-shaped holding arm for holding the bearing , characterized in that : the conductive member comprises a linear U-shaped conductive spring mounted in the holding arm , two ends of the conductive member form curvature parts that protrude in the direction of the bearing towards the inside of the holding arm , a circle shaped twisted part is formed at the center part of the conductive member , the conductive member having a spring force in a direction towards the inside of the holding arm through the twisted part , and part of the linear spring is in electrical contact with the bearing of the transfer roller when the bearing is held by the holding arm . <EOS>