A transfer device of an image forming apparatus comprising: a transfer belt to which images formed on a plurality of photoconductors are transferred; a plurality of transfer rollers corresponding to the plurality of photoconductors , and being movable between transfer positions where the images are transferred to the transfer belt and ready positions separated from the transfer positions; first slider members moving one of the plurality of transfer rollers between the transfer position and the ready position; second slider members moving the remaining transfer rollers between the transfer positions and the ready positions; and a driving unit moving the first slider members and the second slider members , wherein: the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members ; and when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different characterized in that the first cam members and the second cam members are each connected to a cam rotating shaft passing through both the first slider members and the second slider members ; the second slider members extend away from the cam rotating shaft in a first direction; and the first slider members extend away from the cam rotating shaft in a direction opposite to the first direction. a transfer belt to which images formed on a plurality of photoconductors are transferred; a plurality of transfer rollers corresponding to the plurality of photoconductors , and being movable between transfer positions where the images are transferred to the transfer belt and ready positions separated from the transfer positions; first slider members moving one of the plurality of transfer rollers between the transfer position and the ready position; second slider members moving the remaining transfer rollers between the transfer positions and the ready positions; and a driving unit moving the first slider members and the second slider members , wherein: the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members ; and when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different characterized in that the first cam members and the second cam members are each connected to a cam rotating shaft passing through both the first slider members and the second slider members ; the second slider members extend away from the cam rotating shaft in a first direction; and the first slider members extend away from the cam rotating shaft in a direction opposite to the first direction. the driving unit includes first cam members moving the first slider members and second cam members moving the second slider members ; and when the plurality of transfer rollers moves from the transfer positions to the ready positions, a time when movement of the first slider members is completed and a time when movement of the second slider members is completed are different characterized in that the first cam members and the second cam members are each connected to a cam rotating shaft passing through both the first slider members and the second slider members ; the second slider members extend away from the cam rotating shaft in a first direction; and the first slider members extend away from the cam rotating shaft in a direction opposite to the first direction. <EOS>