A developer container includes a casing, a conveying member, a conveying-member accommodating unit, and a supporting member. The casing extends in a longitudinal direction and has a developer accommodating chamber and a waste-developer accommodating chamber and a first opening. The developer accommodating chamber accommodates developer therein. The waste-developer accommodating chamber accommodates waste developer therein. The first opening provides fluid communication between the developer accommodating chamber and outside of the casing. The casing has a first end and a second end opposite the first end in the longitudinal direction. The conveying member is configured to convey the waste developer in a conveying direction defined to be directed from the first end to the second end. The conveying-member accommodating unit is configured to accommodate the conveying member therein. The conveying-member accommodating unit has an upstream end portion and a downstream end portion in the conveying direction. The conveying-member accommodating unit has a second opening and a third opening. The second opening is provided in the upstream end portion and provides fluid communication between inside of the conveying-member accommodating unit and outside of the conveying-member accommodating unit. The third opening provides fluid communication between the inside of the conveying-member accommodating unit and the waste-developer accommodating chamber. The supporting member is provided on the casing. The supporting member supports the conveying-member accommodating unit such that the conveying-member accommodating unit is movable in directions perpendicular to the longitudinal direction relative to the casing.