A developer supply container demountably settable in a developer supply apparatus provided with a rotatable adaptation portion (410, 400c, 9a, 9b), said developer supply container comprising: a container body including an inner space that accommodates a developer and a discharge opening for permitting discharging of the developer; a feeding portion that feeds the developer in said container body toward said discharge opening with rotation of said container body; an erroneous set prevention portion (5, 5a) provided on a peripheral surface of said container body configured and positioned to permit or prevent, after said developer supply container is partially inserted into the developer supply apparatus along a rotational axis direction of said developer supply container, a further inserting operation for setting said developer supply container into the developer supply apparatus depending on the correspondence of said erroneous set prevention portion (5, 5a) to a configuration of the adaptation portion (410, 400c, 9a, 9b); and a leading portion (8, 8a, 8b) configured to rotate the adaptation portion (410, 400c, 9a, 9b) with the inserting operation of said developer supply container to lead the adaptation portion (410, 400c, 9a, 9b) toward said erroneous set prevention portion (5, 5a) irrespective of a rotational position of said erroneous set prevention portion (5, 5a) when said developer supply container is inserted into the developer supply apparatus along an inserting direction (a) of said developer supply container, wherein the leading portion (8, 8a, 8b) has a projection portion having an inclined surface with respect to said rotational axis direction of said developer supply container and is provided on a peripheral surface of said container body at a position downstream of said erroneous set prevention portion (5, 5a) with respect to the inserting direction (a) of said developer supply container. a container body including an inner space that accommodates a developer and a discharge opening for permitting discharging of the developer; a feeding portion that feeds the developer in said container body toward said discharge opening with rotation of said container body; an erroneous set prevention portion (5, 5a) provided on a peripheral surface of said container body configured and positioned to permit or prevent, after said developer supply container is partially inserted into the developer supply apparatus along a rotational axis direction of said developer supply container, a further inserting operation for setting said developer supply container into the developer supply apparatus depending on the correspondence of said erroneous set prevention portion (5, 5a) to a configuration of the adaptation portion (410, 400c, 9a, 9b); and a leading portion (8, 8a, 8b) configured to rotate the adaptation portion (410, 400c, 9a, 9b) with the inserting operation of said developer supply container to lead the adaptation portion (410, 400c, 9a, 9b) toward said erroneous set prevention portion (5, 5a) irrespective of a rotational position of said erroneous set prevention portion (5, 5a) when said developer supply container is inserted into the developer supply apparatus along an inserting direction (a) of said developer supply container, wherein the leading portion (8, 8a, 8b) has a projection portion having an inclined surface with respect to said rotational axis direction of said developer supply container and is provided on a peripheral surface of said container body at a position downstream of said erroneous set prevention portion (5, 5a) with respect to the inserting direction (a) of said developer supply container.