According to the present invention a developer supply container (1) is shown which is detachably mountable to a developer receiving apparatus (10) including a driving gear (12), said container (1) comprising: a cylindrical container (1a) for containing a developer, said cylindrical container (1a) having a developer discharging opening (1b) formed on a peripheral portion thereof; a developer feeding blade (4b) for feeding the developer in said cylindrical container (1a) toward said developer discharging opening (1b) by rotating thereof relative to said cylindrical container (1a) when said cylindrical container (1a) takes a developer discharging position; a drive receiving gear (6) engageable with the driving gear (12) and rotatable about its axis to receive a rotational force for rotating said developer feeding blade (4b) from the driving gear (12); a regulating projection (1g; 100) for regulating a mounting attitude of said cylindrical container (1a) to the apparatus (10) so as to prevent an engagement between said drive receiving gear (6) and the driving gear (12), and thereafter said drive receiving gear (6) is revolvable, with manual rotation of said cylindrical container (1a), in a setting direction (B) about a center of said cylindrical container (1a) to a set position where said drive receiving gear (6) is engageable with the driving gear (12); and a load applier (61, 62, 63, 64) for applying a load to said drive receiving gear (6) to rotate said cylindrical container (1a) from the set position to the developer discharging position by the rotational force received by said drive receiving gear (6).