To provide a developing device capable of preventing the occurrence of the erroneous setting of a toner container, at the time of attaching the toner container to the fitting part of a developing device main body by providing a spring as a pushing back means for pushing back the toner container in a direction opposite to an attaching direction.

An engaging hole 300 and an engaging pawl 301 are formed in a toner receiving case 79 and a color toner container 37, respectively. Further, the spring 305 is attached in the position facing the toner container, of a unit faceplate 45 and a recessed part whose depth is in such a degree that the spring is put in a maximum compressed state is formed in the front surface of the toner container. When a user stops the sliding of the toner container, before the engaging hole is engaged with the engaging pawl, the toner container is pushed back to the front side by repulsion by the spring and the user recognizes that the attachment of the toner container is not completed.