A powder storage container comprising: a powder storage part (32Y2) configured to store a developer used for image forming, a powder discharge part (32Y1d) provided on one end part (32Y1) of the powder storage part (32Y2) to discharge the developer stored in the powder storage part (32Y2), a gripping part (32Y1c) protruding through an end face on the one end part side of the powder storage part (32Y2), a powder loading port causing an inner space of the powder storage part (32Y2) and an outer portion of the powder storage part (32Y2) to communicate with each other, a sealing member capable of sealing the powder loading port, wherein the powder loading port is enclosed by the gripping part (32Y1c), an insertion hole provided in the gripping part (32Y1c) and communicating with the powder loading port, wherein the insertion hole and the powder loading port, which are loading ports of the toner, are through-holes provided by penetrating through the gripping part (32Y1c) on an axial line of the powder storage container and communicate an inner space of the powder storage part (32Y2) with an outer portion of a projection end face (32Y1w) at the gripping part (32Y1c), wherein the sealing member comprises an insertion part inserted into the powder loading port to seal the powder loading port, and a head part provided continuous to the insertion part and extended from the powder loading port in a state where the insertion part seals the powder loading port, and the head part has a length, viewed in a direction extending from the powder loading port, smaller than a length of the insertion hole viewed in an axial direction, characterized in that the insertion hole has a hole shape following an external shape of the gripping part (32Y1c), the head part has an external shape following the hole shape of the insertion hole, a female screw groove serving as a female screw is provided on the insertion part, a male screw groove capable of meshing with the female screw groove at the powder loading port is provided on the insertion part, and the head part has a size enough to form a predetermined clearance between an inner peripheral wall of the insertion hole and an outer peripheral wall of the head part in a state where the insertion part is screwed into the powder loading port. a powder storage part (32Y2) configured to store a developer used for image forming, a powder discharge part (32Y1d) provided on one end part (32Y1) of the powder storage part (32Y2) to discharge the developer stored in the powder storage part (32Y2), a gripping part (32Y1c) protruding through an end face on the one end part side of the powder storage part (32Y2), a powder loading port causing an inner space of the powder storage part (32Y2) and an outer portion of the powder storage part (32Y2) to communicate with each other, a sealing member capable of sealing the powder loading port, wherein the powder loading port is enclosed by the gripping part (32Y1c), an insertion hole provided in the gripping part (32Y1c) and communicating with the powder loading port, wherein the insertion hole and the powder loading port, which are loading ports of the toner, are through-holes provided by penetrating through the gripping part (32Y1c) on an axial line of the powder storage container and communicate an inner space of the powder storage part (32Y2) with an outer portion of a projection end face (32Y1w) at the gripping part (32Y1c), wherein the sealing member comprises an insertion part inserted into the powder loading port to seal the powder loading port, and a head part provided continuous to the insertion part and extended from the powder loading port in a state where the insertion part seals the powder loading port, and the head part has a length, viewed in a direction extending from the powder loading port, smaller than a length of the insertion hole viewed in an axial direction, characterized in that the insertion hole has a hole shape following an external shape of the gripping part (32Y1c), the head part has an external shape following the hole shape of the insertion hole, a female screw groove serving as a female screw is provided on the insertion part, a male screw groove capable of meshing with the female screw groove at the powder loading port is provided on the insertion part, and the head part has a size enough to form a predetermined clearance between an inner peripheral wall of the insertion hole and an outer peripheral wall of the head part in a state where the insertion part is screwed into the powder loading port.