An image forming apparatus comprises a rotatable rotating body to and from
which a plurality of developer containers can be attached and detached,
each of the developer containers being capable of containing developer of
a different color. When the image forming apparatus continuously forms
images on a plurality of number of sheets of media using the developer of
a single color contained in one of the developer containers attached to
the rotating body, the image forming apparatus causes rotational movement
of the rotating body at least once at least either when the image forming
apparatus starts to continuously form the images, or when the image
forming apparatus ends the continuous formation of the images.