Provided are a developer storing container, including a movable moving wall, and suppressing a developer from being leaked to a moving direction upstream side of the moving wall, and an image forming apparatus, provided with the same A toner container is provided with a container main body, a moving wall, a toner discharge port, and an inner wall seal. The toner container replenishes toner to a developing apparatus. The moving wall conveys the toner while being moved toward the toner discharge port inside the container main body. The inner wall seal forms an outer peripheral part of the moving wall, and is compressively deformed between an inner peripheral part of the container main body and the moving wall. A cross-sectional area of an internal space of the container main body is set so as to be decreased as a final position of the moving wall is approached.