A developer container includes a container main body, a supporting member
and an information storage portion. The container main body is formed in
a cylindrical shape and contains therein the developer for use in image
formation. The supporting member supports the container main body
rotatably about an axis. The information storage portion is fixed to the
supporting member and stores developer associated information of the
developer contained in the container main body. The information storage
portion is connected to an information reading portion provided in an
image forming apparatus in such a manner that the information reading
portion can read out the developer associated information in the state
where the developer container is mounted to the image forming apparatus.