An image forming apparatus that is provided with a toner cartridge for holding toner therein, the toner cartridge having a first end and a second end in a longitudinal direction of the toner cartridge, wherein the image forming apparatus comprises: a receiving section in which the toner cartridge is received, the receiving section having a wall configured to face the first end; and an engagement portion provided on the wall; wherein the toner cartridge comprises: a rotary member located at the first end, the rotary member being rotatable about an axis substantially parallel to the longitudinal direction; and an arcuate wall (17a, 17b) formed on the rotary member, the arcuate wall (17a, 17b) extending arcuately about the axis and having a first portion, a second portion, and an inclined portion between the first portion and the second portion; wherein the rotary member is rotatable in the receiving section about the axis from a first position where the engagement portion abuts the first portion, to a second position where the engagement portion abuts the second portion and the toner can be discharged into the image forming apparatus; wherein in the longitudinal direction, the first portion is lower than the second portion and the inclined portion is higher nearer the second portion; and wherein the engagement portion is configured to slide on the arcuate wall (17a, 17b) from the first portion to the second portion through the inclined portion in accordance with rotation of the rotary member about the axis from the first position to the second position, thereby displacing the toner cartridge away from the wall in the longitudinal direction. wherein the image forming apparatus comprises: a receiving section in which the toner cartridge is received, the receiving section having a wall configured to face the first end; and an engagement portion provided on the wall; a receiving section in which the toner cartridge is received, the receiving section having a wall configured to face the first end; and an engagement portion provided on the wall; wherein the toner cartridge comprises: a rotary member located at the first end, the rotary member being rotatable about an axis substantially parallel to the longitudinal direction; and an arcuate wall (17a, 17b) formed on the rotary member, the arcuate wall (17a, 17b) extending arcuately about the axis and having a first portion, a second portion, and an inclined portion between the first portion and the second portion; a rotary member located at the first end, the rotary member being rotatable about an axis substantially parallel to the longitudinal direction; and an arcuate wall (17a, 17b) formed on the rotary member, the arcuate wall (17a, 17b) extending arcuately about the axis and having a first portion, a second portion, and an inclined portion between the first portion and the second portion; wherein the rotary member is rotatable in the receiving section about the axis from a first position where the engagement portion abuts the first portion, to a second position where the engagement portion abuts the second portion and the toner can be discharged into the image forming apparatus; wherein in the longitudinal direction, the first portion is lower than the second portion and the inclined portion is higher nearer the second portion; and wherein the engagement portion is configured to slide on the arcuate wall (17a, 17b) from the first portion to the second portion through the inclined portion in accordance with rotation of the rotary member about the axis from the first position to the second position, thereby displacing the toner cartridge away from the wall in the longitudinal direction.