A container mounting structure includes a container and a container mounting portion. The container extends in one direction and contains powder. The container is mounted to the container mounting portion by rotating the container disposed at a temporarily placed position in a circumferential direction of the container. In a state in which the container is mounted to the container mounting portion, the container mounting structure has contact sections where the container is in contact with the container mounting portion in a radial direction of the container. Each of the contact sections is disposed at corresponding one of at least three different positions in the circumferential direction. The container is in contact with the container mounting portion from inside in the radial direction at one subset of the contact sections and from outside in the radial direction at another subset of the contact sections.