A developer container, which contains a developer to be supplied to a developing chamber in an electrophotographic image forming apparatus, the developer container including: a partition wall partitioning the container from the chamber; a conveying member conveying the developer to an opening in the partition wall to supply the developer to the chamber; a sealing member attached to a wall surface of the partition wall to cover the opening; an extending portion extending from the sealing member to an outside of the container, wherein, when the extending portion is pulled, the sealing member is separated into a remaining portion and a removal portion, and a free end of the remaining portion is positioned below an upper edge of the opening; and a spacing holding member disposed between the wall surface of the partition wall and the sealing member to hold a spacing between the wall surface and the sealing member.