An image forming apparatus includes an intermediary transfer member, image forming units, a voltage source, an executing portion, a setting portion, and a selecting portion configured to select a first mode or a second mode. In the first mode, each of exposure amounts of first and second exposure members is set so that a maximum toner amount per unit area during execution of an image forming operation is a first amount per unit area and a pre-exposure amount is set at a first pre-exposure amount. In the second mode, each of the exposure amounts is set so that the maximum toner amount per unit area is a second amount per unit area smaller than the first amount per unit area, and the pre-exposure amount is set at a second pre-exposure amount larger than the first pre-exposure amount.