A toner cartridge comprising: a toner accommodating unit including a first accommodating portion and a second accommodating portion and configured to accommodate toner, wherein the toner accommodating unit includes a first end portion and a second end portion on a side opposite from the first end portion with respect to a first direction and includes a third end portion and a fourth end portion on a side opposite from the third end portion with respect to a second direction crossing the first direction, wherein the first accommodating portion is on a side closer to the first end portion than to the second end portion in the first direction and the second accommodating portion is on a side closer to the second end portion than to the first end portion in the first direction, wherein the first accommodating portion is provided with a discharge opening for permitting discharge of the toner, accommodated in the first accommodating portion, to an outside of the toner cartridge, the discharge opening being in a position closer to the third end portion than to the fourth end portion in the second direction, and wherein the second accommodating portion is provided with a receiving opening for receiving the toner from the outside of the toner cartridge to the second accommodating portion, the receiving opening being positioned closer to the third end portion than to the fourth end portion in the second direction; characterised by a light transmitting portion having an incident surface and an emergent surface, wherein the incident surface is configured so that light is capable of being incident from the outside of the toner cartridge into an inside of the second accommodating portion, wherein the emergent surface is configured so that the light incident into the inside of the second accommodating portion through the incident surface is capable of emerging to the outside of the toner cartridge, and wherein the incident surface and the emergent surface are provided in positions closer to the fourth end portion than to the third end portion in the second direction and are exposed to the outside of the cartridge. a toner accommodating unit including a first accommodating portion and a second accommodating portion and configured to accommodate toner, wherein the toner accommodating unit includes a first end portion and a second end portion on a side opposite from the first end portion with respect to a first direction and includes a third end portion and a fourth end portion on a side opposite from the third end portion with respect to a second direction crossing the first direction, wherein the first accommodating portion is on a side closer to the first end portion than to the second end portion in the first direction and the second accommodating portion is on a side closer to the second end portion than to the first end portion in the first direction, wherein the first accommodating portion is provided with a discharge opening for permitting discharge of the toner, accommodated in the first accommodating portion, to an outside of the toner cartridge, the discharge opening being in a position closer to the third end portion than to the fourth end portion in the second direction, and wherein the second accommodating portion is provided with a receiving opening for receiving the toner from the outside of the toner cartridge to the second accommodating portion, the receiving opening being positioned closer to the third end portion than to the fourth end portion in the second direction; characterised by a light transmitting portion having an incident surface and an emergent surface, wherein the incident surface is configured so that light is capable of being incident from the outside of the toner cartridge into an inside of the second accommodating portion, wherein the emergent surface is configured so that the light incident into the inside of the second accommodating portion through the incident surface is capable of emerging to the outside of the toner cartridge, and wherein the incident surface and the emergent surface are provided in positions closer to the fourth end portion than to the third end portion in the second direction and are exposed to the outside of the cartridge.