A developer supply container is mountable to a developer receiving apparatus including a driving gear, and includes a developer discharging opening; a feeding blade for feeding the developer toward the opening when the container is positioned at a developer discharging position; a drive receiving gear engageable with the driving gear for rotating the feeding blade; a regulating projection for regulating a mounting attitude of the container to prevent engagement between the drive receiving and driving gears. Upon mounting the container, the drive receiving gear is revolvable, with manual rotation of the container, about a rotation center of the container to a set position where the drive receiving gear engages with the driving gear; and a load applier for applying a load to the drive receiving gear to rotate the container from the set position to the discharging position by the rotational force received by the drive receiving gear.