An image forming apparatus for forming an image on a recording material comprising: a first image forming unit (Pa), one of a plurality of image forming units (Pa, Pb, Pc, Pd), positioned on one endmost side in an arrangement direction of the plurality of image forming units (Pa, Pb, Pc, Pd), said first image forming unit (Pa) including a first photosensitive member, a first charging unit configured to charge said first photosensitive member by corona discharge and a first developing unit configured to develop an electrostatic latent image formed on said first photosensitive member with toner; and a second image forming unit (Pd), another one of the plurality of image forming units (Pa, Pb, Pc, Pd), positioned on the other endmost side in the arrangement direction, said second image forming unit (Pd) including a second photosensitive member, a second charging unit configured to charge said second photosensitive member by corona discharge and a second developing unit configured to develop an electrostatic latent image formed on said second photosensitive member with toner; a first fan provided closer to a first edge of the image forming apparatus in the arrangement direction than said first image forming unit (Pa) is to the first edge, said first fan sucking outside air to supply from a first suction port to said first image forming unit (Pa), and the first suction port being positioned closer to said first image forming unit (Pa) in the arrangement direction than to said second image forming unit (Pd); and a second fan provided closer to a second edge of the image forming apparatus in the arrangement direction, the second edge being opposite to the first edge, than said second image forming unit (Pd) is to the second edge, said second fan sucking outside air to supply from a second suction port to said second image forming unit (Pd), and the second suction port being positioned closer to said second image forming unit (Pd) in the arrangement direction than to said first image forming unit (Pa); wherein said first fan is positioned closer to said first image forming unit (Pa) in the arrangement direction than to said second image forming unit (Pd), and wherein said second fan is positioned closer to said second image forming unit (Pd) in the arrangement direction than to said first image forming unit (Pa). a first image forming unit (Pa), one of a plurality of image forming units (Pa, Pb, Pc, Pd), positioned on one endmost side in an arrangement direction of the plurality of image forming units (Pa, Pb, Pc, Pd), said first image forming unit (Pa) including a first photosensitive member, a first charging unit configured to charge said first photosensitive member by corona discharge and a first developing unit configured to develop an electrostatic latent image formed on said first photosensitive member with toner; and a second image forming unit (Pd), another one of the plurality of image forming units (Pa, Pb, Pc, Pd), positioned on the other endmost side in the arrangement direction, said second image forming unit (Pd) including a second photosensitive member, a second charging unit configured to charge said second photosensitive member by corona discharge and a second developing unit configured to develop an electrostatic latent image formed on said second photosensitive member with toner; a first fan provided closer to a first edge of the image forming apparatus in the arrangement direction than said first image forming unit (Pa) is to the first edge, said first fan sucking outside air to supply from a first suction port to said first image forming unit (Pa), and the first suction port being positioned closer to said first image forming unit (Pa) in the arrangement direction than to said second image forming unit (Pd); and a second fan provided closer to a second edge of the image forming apparatus in the arrangement direction, the second edge being opposite to the first edge, than said second image forming unit (Pd) is to the second edge, said second fan sucking outside air to supply from a second suction port to said second image forming unit (Pd), and the second suction port being positioned closer to said second image forming unit (Pd) in the arrangement direction than to said first image forming unit (Pa); wherein said first fan is positioned closer to said first image forming unit (Pa) in the arrangement direction than to said second image forming unit (Pd), and wherein said second fan is positioned closer to said second image forming unit (Pd) in the arrangement direction than to said first image forming unit (Pa).