A developer container includes a developer storage chamber that stores developer and includes an opening, a sealing member that seals the opening, an unsealing member that opens the opening by rotating such that the sealing member, a part of which is attached to the unsealing member, is peeled away, a stirring member that is attached to the unsealing member; and a regulating portion that regulates rotation of the unsealing member by contacting the stirring member. The regulating portion is provided to regulate the rotation of the unsealing member when the developer container receives an external force, and allow the unsealing member to rotate such that the opening is opened when the unsealing member receives driving power.