An image forming apparatus comprising: an image bearing member configured to bear a toner image; a transfer member (44, 45) configured to transfer a toner image onto a recording material from the image bearing member; application means (75, 76) for applying a voltage to the transfer member; discharge means for discharging a recording material including an image formed by fixing a toner image transferred by the transfer member; a platen on which a recording material is disposed when an image on the recording material is to be read; a reading device configured to read density information of an image on a recording material disposed on the platen; and control means for executing an adjustment mode for adjusting a transfer voltage to be applied to the transfer member by the application means in a transfer process, by discharging, from the discharge means, a first recording material including a first chart formed by sequentially transferring a plurality of test images by applying a plurality of test voltages to the transfer member by the application means, and a second recording material including a second chart formed by sequentially transferring a plurality of test images by applying a plurality of test voltages to the transfer member by the application means, wherein the control means is configured to adjust the transfer voltage based on a reading result of density information of the test images on the first chart and the second chart that is obtained by the reading device, characterized in that the reading result is obtained by the reading device reading the first recording material and the second recording material disposed together on the platen, and wherein first page identification information for identifying page information of the first chart is formed on a surface on which the first chart is formed, and second page identification information for identifying page information of the second chart is formed on a surface on which the second chart is formed, and wherein the control means is configured to adjust the transfer voltage based on a reading result of the first page identification information and the second page identification information that is obtained by the reading device. an image bearing member configured to bear a toner image; a transfer member (44, 45) configured to transfer a toner image onto a recording material from the image bearing member; application means (75, 76) for applying a voltage to the transfer member; discharge means for discharging a recording material including an image formed by fixing a toner image transferred by the transfer member; a platen on which a recording material is disposed when an image on the recording material is to be read; a reading device configured to read density information of an image on a recording material disposed on the platen; and control means for executing an adjustment mode for adjusting a transfer voltage to be applied to the transfer member by the application means in a transfer process, by discharging, from the discharge means, a first recording material including a first chart formed by sequentially transferring a plurality of test images by applying a plurality of test voltages to the transfer member by the application means, and a second recording material including a second chart formed by sequentially transferring a plurality of test images by applying a plurality of test voltages to the transfer member by the application means, wherein the control means is configured to adjust the transfer voltage based on a reading result of density information of the test images on the first chart and the second chart that is obtained by the reading device, characterized in that the reading result is obtained by the reading device reading the first recording material and the second recording material disposed together on the platen, and wherein first page identification information for identifying page information of the first chart is formed on a surface on which the first chart is formed, and second page identification information for identifying page information of the second chart is formed on a surface on which the second chart is formed, and wherein the control means is configured to adjust the transfer voltage based on a reading result of the first page identification information and the second page identification information that is obtained by the reading device.