Toner cartridge capable of preventing sealing film from breaking

A toner cartridge comprising:

• a developing chamber having a side wall;
• a toner chamber holding toners;
• a partition disposed between the developing chamber and the toner chamber, the partition dividing the developing chamber and the toner chamber, the partition having a main surface facing toward the developing chamber;
• a toner supply opening formed through the main surface of the partition for supplying toners from the toner chamber to the developing chamber;
• the side wall having an opening, the side wall having an edge defining a side of the opening and being disposed at one end of the partition and proximate the main surface;
• a sealing film having a toner chamber side and an opposed developing chamber side and affixed on said toner chamber side to the main surface to close the toner supply opening for sealing the toners within the toner chamber when the toner cartridge is in an unused state, the sealing film being peelable from the main surface to permit toner to be supplied from the toner chamber to the developing chamber, the sealing film being bent upon itself to form a bent section for peeling the film from the main surface and removing the film through the opening through the side wall;
• and
• a step disposed between the edge of the side wall and the main surface, the step forming an escape for toner gathered within the bent section of the sealing film during peeling of the film from the main surface.