A color electrophotographic image forming apparatus comprising: a main body; a plurality of cartridges including cartridge side electric contacts; main body side positioning portions provided on the main body of the color electrophotographic image forming apparatus for the plurality of cartridges, respectively; main body side electric contacts provided on the main body for the plurality of cartridges, respectively, the main body side electric contacts being electrically connected to the cartridge side electric contacts by a movement of a cartridge supporting member from a second position to a first position; a pressing member that presses the plurality of cartridges in association with a movement operation of the cartridge supporting member from the second position to the first position so as to press cartridge side positioned portions onto the main body side positioning portions; and said cartridge supporting member to which the cartridges are detachably attached, wherein in a state where the cartridge supporting member supports the respective cartridge, the cartridge supporting member being movable among (i) a first inside position as said first position of the main body where the cartridge is located at an image forming position at which the cartridge forms an image and the cartridge side electric contacts and the main body side electric contacts directly contact each other so as to be electrically connected to each other, (ii) a second inside position as said second position of the main body where the cartridge supporting member is retracted from the first inside position and the cartridge side electric contacts and the main body side electric contacts are spaced from each other, and (iii) an outside position of the main body where the cartridge is pulled from the main body, wherein the main body further includes an opening portion through which the cartridge supporting member is moved from the inside of the main body to the outside of the main body, and an openable and closable member provided on the main body for opening and closing the opening portion, wherein the cartridge supporting member is moved between the first inside position and the second inside position in association with the openable and closable member, and wherein in a state where the cartridge supporting member is in the first inside position and the cartridge side electric contacts and the main body side electric contacts directly contact each other, the cartridge side electric contacts are arranged on a lower surface on one end side of the cartridge in a longitudinal direction of the cartridge. a main body; a plurality of cartridges including cartridge side electric contacts; main body side positioning portions provided on the main body of the color electrophotographic image forming apparatus for the plurality of cartridges, respectively; main body side electric contacts provided on the main body for the plurality of cartridges, respectively, the main body side electric contacts being electrically connected to the cartridge side electric contacts by a movement of a cartridge supporting member from a second position to a first position; a pressing member that presses the plurality of cartridges in association with a movement operation of the cartridge supporting member from the second position to the first position so as to press cartridge side positioned portions onto the main body side positioning portions; and said cartridge supporting member to which the cartridges are detachably attached, wherein in a state where the cartridge supporting member supports the respective cartridge, the cartridge supporting member being movable among (i) a first inside position as said first position of the main body where the cartridge is located at an image forming position at which the cartridge forms an image and the cartridge side electric contacts and the main body side electric contacts directly contact each other so as to be electrically connected to each other, (ii) a second inside position as said second position of the main body where the cartridge supporting member is retracted from the first inside position and the cartridge side electric contacts and the main body side electric contacts are spaced from each other, and (iii) an outside position of the main body where the cartridge is pulled from the main body, wherein the main body further includes an opening portion through which the cartridge supporting member is moved from the inside of the main body to the outside of the main body, and an openable and closable member provided on the main body for opening and closing the opening portion, wherein the cartridge supporting member is moved between the first inside position and the second inside position in association with the openable and closable member, and wherein in a state where the cartridge supporting member is in the first inside position and the cartridge side electric contacts and the main body side electric contacts directly contact each other, the cartridge side electric contacts are arranged on a lower surface on one end side of the cartridge in a longitudinal direction of the cartridge.