A toner container comprising: a toner container main body having a predetermined length and including an upper case and a lower case and in which toner is accommodated; a discharge port formed on one side of the lower case (in a width direction) and configured such that the toner is discharged from the toner container main body through the discharge port; a screw provided on one side of the interior of the toner container main body in a width direction and configured to convey the toner to the discharge port; and a mixer configured to stir the toner in the toner container main body; characterized in that the upper case comprises a first curvature portion on an inner wall closer to the screw and bent at a first curvature (κ1) and a second curvature portion on an inner wall opposite to the screw and bent at a second curvature (κ2), the second curvature (κ2) being larger than the first curvature (κ1) and the mixer is configured to move along an inner peripheral surface of the first curvature portion, the upper case comprises a turn-up portion which rises from a lower end of the first curvature portion, and the turn-up portion, in association with the lower end of the first curvature portion, defines a sharp portion, the mixer includes a shaft member, and the shaft member is provided so as to substantially coincide with the center of radius of the first curvature of the first curvature portion, the upper case comprises a first rib and the lower case comprises a second rib, the first and the second ribs facing each other, and a parting sur-face located between the first rib and the second rib being located above the shaft of the mixer, and the lower end of the first curvature portion extends below the parting surface and is connected to the first rib via the turn-up portion. a toner container main body having a predetermined length and including an upper case and a lower case and in which toner is accommodated; a discharge port formed on one side of the lower case (in a width direction) and configured such that the toner is discharged from the toner container main body through the discharge port; a screw provided on one side of the interior of the toner container main body in a width direction and configured to convey the toner to the discharge port; and a mixer configured to stir the toner in the toner container main body; characterized in that the upper case comprises a first curvature portion on an inner wall closer to the screw and bent at a first curvature (κ1) and a second curvature portion on an inner wall opposite to the screw and bent at a second curvature (κ2), the second curvature (κ2) being larger than the first curvature (κ1) and the mixer is configured to move along an inner peripheral surface of the first curvature portion, the upper case comprises a turn-up portion which rises from a lower end of the first curvature portion, and the turn-up portion, in association with the lower end of the first curvature portion, defines a sharp portion, the mixer includes a shaft member, and the shaft member is provided so as to substantially coincide with the center of radius of the first curvature of the first curvature portion, the upper case comprises a first rib and the lower case comprises a second rib, the first and the second ribs facing each other, and a parting sur-face located between the first rib and the second rib being located above the shaft of the mixer, and the lower end of the first curvature portion extends below the parting surface and is connected to the first rib via the turn-up portion.