An image forming apparatus includes a first image bearing member carrying a toner image, and a movable second image bearing member carrying a toner image. The toner image on the first image bearing member is transferred to the second image bearing member at a first transfer portion, and the toner image on the second image bearing member is transferred to a transfer material at a second transfer portion. The apparatus also includes a charging member contacting the second image bearing member arranged on a downstream side of the second transfer portion and on an upstream side of the first transfer portion in a moving direction of the second image bearing member, and a mark portion having a thickness and being formed on the second image bearing member. A contact region between the charging member and the second image bearing member does not overlap with the mark portion in a direction perpendicular to the moving direction of the second image bearing member.