A developer container includes a container, provided with an opening and configured to accommodate a developer; a sealing member configured to cover the opening; and an unsealing member configured to unseal the opening by moving the sealing member. The sealing member opposes the container at a central opposing portion positioned in a central side and at an end opposing portion positioned at an end side with respect to a longitudinal direction of the unsealing member. The sealing member and the container are bonded to each other at bonding portion which is at least a part of the central opposing portion. The bonding force at the bonding portion of the central opposing portion is larger than a bonding force between the sealing member and the container at the end opposing portion.