A developer accommodating container for accommodating a developer for image formation, includes a first flexible member having a three-dimensional shape; a second flexible member for forming a space for accommodating the developer by covering a part of the first flexible member; wherein the developer accommodating container is constituted by bonding the first flexible member and the second flexible member to each other, and an injection opening, provided between the first flexible member and the second flexible member, for permitting injection of the developer into the developer accommodating container. An adjacent side, which is one of sides constituting an outer configuration of the three-dimensional shape and which is adjacent to the injection opening, has an angle of less than 90 degrees with respect to an injection direction of the developer at the injection opening.