An image forming apparatus includes a developer bearing member, a frame having a storage member, and a first temperature detection unit. The storage member is for storing a developer for the developer bearing member to record an image on a recording material. The storage member includes an attachment part in which a supply container enclosing a developer is removably attachable to the attachment part. With reference to a recording material conveyance path having a center in a width direction of the recording material that is orthogonal to a recording material conveyance direction and in a case where an area on one side of the conveyance path center is a first area and the area on the other side of the conveyance path center is a second area, the attachment part is arranged in the first area and the first temperature detection unit is arranged in the second area.