An image forming apparatus includes a main body, a cover to open and close a front of the main body, a tray slidably mounted in the main body through the front of the main body, at least one developing cartridge mounted in the main body in a state in which the developing cartridge is received in the tray, at least one driving coupler member provided at one side of the main body to drive the developing cartridge mounted in the main body, a link member operating simultaneously with opening and closing of the cover to move in a first direction, and a guide member to support the at least one driving coupler member, the guide member operating simultaneously with the link member to move in a second direction perpendicular to the first direction, wherein the guide member is pressed by the link member, when the cover opens the main body, to separate the driving coupler member from the developing cartridge.