Electrophotographic image forming apparatus

An image forming apparatus for forming an image on a recording material, comprising:

• a drum cartridge supporting member for supporting a plurality of drum cartridges each including an electrophotographic photosensitive drum, wherein said drum cartridge supporting member is movable, with respect to an axial direction of the electrophotographic photosensitive drum, between a first position inside a main assembly of said image forming apparatus and a second position, outside the main assembly, in which the drum cartridges are mountable and dismountable;
• a guide portion for guiding a plurality of developing cartridges each including a developing roller for developing an electrostatic latent image formed on the electrophotographic photosensitive drum, wherein said guide portion individually guides the developing cartridges mountably to and demountably from the main assembly in an axial direction of the developing roller;
• and
• moving means for moving the developing cartridge mounted in the main assembly between a developing position in which the electrostatic latent image is to be developed and a retracted position in which the developing cartridge is retracted from the developing position, wherein when the developing cartridge is in the retracted position, said drum cartridge supporting member is permitted to move between the first position and the second position.