Cartridge supporting member having different moving direction guide portions

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

• a cartridge supporting member movable between an inside position in which said cartridge supporting member is inside a main assembly of said image forming apparatus in a state of carrying a first cartridge and a second cartridge, each of which includes a developing roller, and a drawn position in which said cartridge supporting member is outside said main assembly of said apparatus and in which said first cartridge and said second cartridge are mountable and demountable relative to said cartridge supporting member, wherein said cartridge supporting member includes a first mounting portion to which said first cartridge is mountable, and a second mounting portion to which said second cartridge is mountable, said second mounting portion being disposed upstream of said first mounting portion with respect to a drawing direction in which said cartridge supporting member is moved from the inside position to the drawn position;
• a belt member configured to contact a plurality of photosensitive drums when said cartridge supporting member is positioned at the inside position;
• a first guide portion, provided on said cartridge supporting member, for guiding mounting and dismounting of said first cartridge relative to said first mounting portion;
• and
• a second guide portion, provided on said cartridge supporting member, for guiding mounting and dismounting of said second cartridge relative to said second mounting portion,
• wherein said first cartridge is dismounted from said first mounting portion in a first moving direction within said cartridge supporting member guided by said first guide portion, and said second cartridge is dismounted from said second mounting portion in a second moving direction within said cartridge supporting member guided by said second guide portion, wherein said second guide portion has a guiding portion that includes an inclined guiding portion which is inclined toward the drawing direction more than a guiding portion of said first guide portion, and the second moving direction is different from the first moving direction.