The disclosed structure includes a belt-shaped conveying member configured to convey developer. The conveying member includes a partitioning portion, which is a partition for developer contained in a casing with respect to a conveying direction in which the developer is conveyed, wherein, when the developer container is new, a first developer amount which is an amount of the developer contained at an upstream side that is upstream of the partitioning portion in the conveying direction, is larger than a second developer amount which is an amount of the developer contained at a downstream side that is downstream of the partitioning portion in the conveying direction.