An image forming apparatus of the present invention is composed by an image bearing member that bears a toner image; an intermediate transferring material that contacts with the image bearing member; a transferring unit that transfers a toner image on the image bearing member to the intermediate transferring material at a transferring position; a bias applying unit that applies a bias to a power supply portion of the transferring unit during a period in which transfer is performed by the transferring unit; a cleaning unit that contacts with the image bearing member and cleans the surface of the image bearing member; a toner supplying unit that, when an image is not being formed, passes a toner image for supply that is formed on the image bearing member through the transferring position to supply the toner image for supply to the cleaning unit; and a switching unit that switches from a state in which the power supply portion is electrically connected to the bias applying unit to a state in which a resistance value between the power supply portion and a ground is 100 MΩ or more.